All of that is still pretty minor, no matter how you put it. It's just skins and textures in a game that's not even part of its own series, so yes, that's significantly less compared to an actual game. Everything else in Smash had at least one game on a Nintendo console featuring a character before they appeared in that Smash game. It would be kind of silly to say a character should also be in just because of skins and textures from a separate game.
I mean, if you actually read what I said, you'd know that's not the whole story. First, DLC models prove what you said wrong; if stuff costs more, it's because it has more content. They are not identical levels of content no matter how you go about it. That's just basic business. It costs more because it requires more. In addition, the reason mash-up packs cost more is because it includes some notable things; normally include modifications to the title screen, a skin pack, a texture pack, and a themed world; many also include themed music tracks or make them available for download. The second you turn a game into another themed version of it, that's not a "minor" change. That's a pretty major change to the game itself. That's why there's a major price jump.
Second, the reason wasn't simply "they showed jump in a fairly major way within the game's settings"(in practice, that's the case). What also is important is that Microsoft puts their exclusive content on Nintendo's systems overall within a crossover in another game. And not just a bunch of skins, but outright represented the world. What it means is Microsoft is okay with collaborating with Nintendo overall when it comes to exclusive content. This is why it's actually much weirder Halo has no content in Smash. It's not just a fairly major gameplay crossover piece, it's that it's a big deal with how it happened. This is also part of why Microsoft and Nintendo are so chummy with each other. They're in very good graces, which is part of what led to us even having Microsoft content in Smash. Minecraft alone was already in talk as of 2015. That Halo Mash-Up Pack? Also 2015. That's kind of a big deal, since as early as that, they've collaborated with their content. Though we don't know exactly when talks of Steve started in 2015, Halo's Mash-Up Pack was in October. Either way, they happened around a pretty similar time, so they could've affected each other by quite a bit. After getting that content, Sakurai or Nintendo could've easily talked with them about the concept, and knowing how well they collaborate, it's easy to see why the timing is so close. Besides that, we did get an Minecraft 3DS design created by Microsoft, so it's basically showing that the Nintendo trusted them a lot. But more importantly, that it's pretty hard to say Nintendo nor Microsoft would say no to the idea. You seemed to have missed the core point, in which that only Sakurai would be the reasonable with all this information known, to not want to add Halo to the line-up of Smash content. Nintendo heavily trusts Microsoft, and vice versa. So there's no real reason to believe they'd say no. Whether it's because Sakurai never thought of it, or didn't like the idea, or anything else not related to Nintendo and Microsoft, who knows. It could even be something closer to "the licensing just was too much in the end", a valid reason why the companies decided to not go with it. Costumes in Smash, while not terribly large content, do require a bit more work than said skins(but to be fair, those skin packs are basically spirits while the mash-up packs are actually still the equivalent to a full character pack in practice and content. And either way, require quite a bit more work. User Interface changes, as I've noted before, are actually not very simple to do. While it may seem like the idea of game mods are pretty simple cause so many exist, most are broken messes and very few actually are near glitch-free anyway. They're actually pretty difficult in practice and takes a lot of time and work. And the reality is, those mash-up packs are basically normal game mods that cost money in Minecraft. They don't charge for basic updates or sometimes exclusive skins/mash-up packs, but that's it.
I'm...not sure exactly what you're getting at. What you were talking about was somewhat unrelated what I was saying, as I didn't mention anything about when the game was in development, as I already stated. What I was talking about was if the game had been an earlier Switch title alongside the others I mentioned. So not only was it strange for you ask me that, it should be no surprise if I couldn't answer that because that's info only the company can give out. Even in what you found, it just said it was teased, which really isn't enough to explain what's going on with the development. Because the truth is, aren't any details.
I'm not being weird or defensive about it. It's just that I found your response to be kind of awkward, as if you were really expecting me to answer something that had nothing to do with what I said and I couldn't possibly know about at this moment either.
Besides being entirely related to what would make your hypothetical in any way possible, the tease time means it's been in development for a while now, which does give us a legitimate and educated guess to when it was developed. It means the game entirely has a full concept, various details were given, and in any case, how much gameplay is seen during a tease tells if it's been straight-out developed or still in the planning phase. However, seeing as how the game got teased in 2020, that means enough work was done development-wise that a simple spirit didn't miss the boat. It released in early 2022 too, and Smash's DLC finished in late 2021, keep in mind. The actual timeline shows that development time wasn't actually an issue at all.
What's more the case if what we saw, a major lack of any Spirit DLC beyond the Fighter's Pass. So it's less so development time and more that they already made plans and weren't going to add more. As the game was teased to be playable in 2021 from the start. So we already knew a delay outright happened. That means it had to have been pretty far in development before the tease as is. So it didn't exactly miss the boat. To further clarify, it's far more likely what really happened is the delay would've caused too many changes, making it impossible to get any kind of Spirit option that remained accurate. It was easily development early enough(over a year before Smash Ultimate ended), and the latest spirit we got was January 2022. Which is even after the normal DLC was finished. The timeline doesn't really show it being "started development early enough"(nor would the release have mattered much either), it looks more like, with all information given, it had development problems instead. Considering the last game was in 2018, it's pretty safe to say they didn't wait two whole years to start development. It's far more likely to maybe be 1 year or even less than that it started.
So keeping in mind the release isn't that notable anyway, let's go back to what I mean by Spirit DLC. The data indicates they had already selected them pretty early on. Now, let's also keep in mind that we have more than enough reason to believe by at least close to 2019 bare minimum(note the data above and how game development works) that Forgotten Land would begin development(this is major leeway, though. We also know they've been trying to make a new 3D entry since 2010, so who knows when a lot of information was started and put on the backburner, respectively), but more to the point, it wouldn't have "missed the boat" since 2019 was actually when we started getting DLC in general released. Thus, with these details in mind, it goes back to what I was saying. The release alone isn't as relevant as to why the development would take so long. What was changed? How much was changed from the teaser? Was it because of spoilers alone? While the release could've played a, heh, minor role, the time it took to development and why it took a year extra is specifically in correlation to why it couldn't get a spirit. Basically, the more time it takes to make, the harder it is to select what to cameo from the game, as there can be many reasons why. They're similar things, but the development's start and finish also plays a massive role in this situation. Of course, if we were talking about a playable character, release take priority since they wouldn't want to drop a character who wouldn't be available to play their game till months on later, especially when any and all DLC has an advertising effect. Hence, spirits would be fine.
I should be clear that I was curious about the development, because it was the only way to actually answer your question. Would it being released earlier be enough? Maybe. But that entirely depended upon when the development first started, because that's when a bare minimum release can happen. They always correlate, cause.... basic game creation.