Some good points are made, it is entirely possible that these Mallow & Cacodemon costumes were being made ahead of time and will be released later on (we'll know soon enough). However, I will say just because we didn't see Geno & Doomguy Mii Costume doesn't mean they don't exist. I made a vow to never take the absence of a character/product to be an indicator of a character getting in (I got burned super hard with Shadow how we started having third party echo fighters, Knuckles coming in as an Assist Trophy, and fact that he is one of the easiest Assist Trophy to make since all he does is stand still slow down time just like the Timer item so it was surprising to see him gone for a long time). There's a possibility that they do actually exist, all we got to work with is that video.
Good point, but I think it's a bit different with regards to Geno's costume. If Geno's costume and the Mallow hat were ready around July, why wouldn't they just release them both during Hero's presentation alongside the other SquareEnix costumes? They're all owned by the same company, so it would make sense, but they weren't. Not only that, but every single leak/credible rumor we've had that had to do with SMRPG stuff has consistently left out any mention of Geno or his costume. Geno's costume is (no pun intended) old hat, it's nothing new, so why the hell has old costume not been discovered by now when, realistically speaking, we should've heard about it by now?
PapaGeno's source listed Mallow/Smithy, no Geno.
This leaked video has Mallow Hat, no Geno.
Like, am I supposed to believe that all of these insiders/leakers are all trying to hide the Geno costume in tandem? Am I to assume every one of these insiders/leakers are doing the same troll at the same damn time? Chrom or Shadow being absent in promotional material is one thing, but this? This goes way beyond mere coincidence, if you ask me.
For the Doomguy counter point I will say that we got Mii Costumes from series that haven't been represented in Smash Bros before, like Goemon, Virtua Fighter, Tekken, and Monster Hunter to name a few. Sure, they all came from companies that already had involvement with Smash Bros, but we also have Rayman as a Spirit and Yuri Kozukata as an Assist Trophy despite the fact that Ubisoft & Koei Tecmo don't have a character represented in Smash Bros at all. So what's so crazy about them including Mii Costumes of the Doom series without a playable character? It's entirely possible that they would go out of their way to contact Bethesda for something like this.
Becuase that would mean that Nintendo took the time to go out to Bethesda, an american company, to negotiate DLC content for Smash, and either Nintendo or Bethesda decided that all they wanted/were willing to provide, was a Doomguy Costume and a Cacodemon Hat.
With regards to Nintendo, why would you go out of your way to negotiate with a foreign company and NOT want to get a playable character out of them? Sure, they've done that with Wayforward and Ubisoft, but that was only for spirits, which was probably all they could include at the time. Recall that Sakurai has stated that he mostly never deviates from the project plan when he's finished it.
So when time came to negotiate with Ubisoft or Wayforward, they couldn't get their characters in as fighters, but they could as spirits since they're just PNGs with stats attached to them, which makes them easier to include, project plan be damned. But a DLC Mii Fighter costume? Unless that company is really easy to negotiate with, ie. a Japanese company like Konami, there's no way they'd do that all for just a simple costume. It would be like them going to Microsoft for just a Banjo or Minecraft costume, and they sure as hell didn't do that with Banjo.
And with regards to Bethesda? There are plenty of companies literally throwing themselves at the opprotunity to have their characters represented in Smash, it's one of if not the biggest celebration of video games in history, anyone who's anyone is in this game. You're telling me that Nintendo came to Bethesda to use their characters, and Bethesda for some reason DIDN'T want to push for getting one of their flagship character in Smash as a fighter? They only wanted some Mii Fighter costumes? If you went to Wayforward, Yacht Club Games, Nicalis, IntiCreates, Playtonic, Ubisoft, Microsoft, Sony, or even Disney, and offered to put one of their characters into Smash as a fighter, they wouldn't hesitate to make that happen. and the same would go for Bethesda.
And sure, Sans got in only as a Mii Fighter, and... yeah I'll admit I have no idea what went on behind the scenes there.
Perhaps they had already decided on a bunch of other characters and couldn't fit Sans into Smash as a fighter.
Or maybe Toby specifically wanted Sans as a Mii Fighter costume because of how in-character it would be for Sans to just take someone else's moveset rather than coming up with his own.
Or maybe these negotiations were done before they decided to make more DLC fighters post-Fighters Pass.
Or maybe Sakurai had no interest in Sans as a fighter and was just doing Toby a solid.
Or maybe Toby didn't care how Sans got into Smash and was happy with whatever?
Again, I have no idea, but in most instances companies would be entirely fine with providing their characters as fighters for Smash, so why would Bethesda be any different?
Also I wouldn't use the fact that we would've heard about a Doomguy & Geno costume by now considering that with the last Mii Costume leak that we got which mentioned Mallow & Smithy didn't mention Cacodemon at all.
We also didn't hear about the Sans costume at all, but the list still got 4/7 costumes correct, with the Mallow hat bumping that up to 5/7, so... yeah.
The biggest hit to this leak in my opinion is the fact that it doesn't show Terry in any way. If the leaker has access to these costumes, he should also have access to Terry; then why didn't they show him, or his stage? It would add a ton of credibility to this leak.
He did show Terry, he was just using the hatless alt.