We already know for a fact that the whole FP2 roster wasn't planned after the game's release.
We heard words from an ex-Mojang employee that Steve has been in talks since 2015, and Sakurai, the man himself, also already intended on adding one or two more characters. We don't know who he meant, but he clearly already had plans for some characters.
And I'm willing to bet that Sakurai thought about adding Rex in the base game but couldn't make it work as he said in the recent presentation. Thus, knowing that he would never manage to make Rex work in a duo with Pyra and Mythra, went on to add the Mii costume as way to excuse himself for being unable to add Rex. No, I don't have proof, but I sincerely think the team already had a route on who to add as DLC from the start. After all, they planned the roster for Ultimate three years prior its release, why not the same for the whole DLC roster?
I'm not arguing against the bad timing, mind you, however I believe even before the game released, Sakurai already made the list for the second pass. Characters are, after all, the first thing they decide, even more in the case of DLC where they only have characters to work on as well as a smaller team. That's at least how I pushed the idea Sephiroth would definitely be DLC due to Sakurai's words and the lack of FFVIIspirits, and why I thought Rex had a chance despite the costume (however I didn't think Sakurai would put Pyra instead of him, man).
I could be proven wrong with an unexpected spirit promotion, but I'm confident that we won't see that happen again. If that happens I'll photoshop a cube of shame on my avatar's head.
The thing with Steve is there being talks doesn’t mean he was guaranteed, they were just talks, otherwise he probably would’ve been in the basegame or FP1. Thankfully they came to an agreement and got him in for FP2, or whatever bonuses they may have had before deciding to do a full second pass. Talks can lead to nothing if no agreement is made, and thankfully that wasn’t the case here (“thankfully” as my personal opinion of course).
My reason for believing FP2 was planned after basegame is because Imran Khan (the insider dude), at around 17:02 in this video:
https://youtu.be/58WAbKCJ06A, said it was decided around E3 that year (2019), and that they were considering how FP1 sells. Of course, at least a couple of characters may have been planned already according to Sakurai’s word if he wasn’t just teasing a little (iirc he said that just before the 6 fighter reveal but idk), maybe them being Steve and Sephiroth, but still, even if FP2 was planned just a couple months after basegame, that would imply basegame spirits don’t matter since they’d now have new plans/opportunities.
According to some in-the-know people on this site, FP1 also seemed to have its plans done in 2018, putting FP2 at a similar timeline if it started in 2019. This included Banjo & Kazooie being negotiated in April 2018 (and I think something said by Rare or whoever fit this timeline closely, maybe a little off). Sakurai’s words seem to imply the FP1 thing too since apparently the devs didn’t know about it before January 2018 iirc (he said it in one of his columns in early 2019 iirc if not December 2018).
iirc Sakurai’s words about Rex seemed to imply they had him in mind with Pyra & Mythra with him for DLC but then they found it to be harder than the Ice Climbers, so they just went with Pyra & Mythra and still had Rex in a taunt, the final smash, and a victory screen at least. So it seemed Rex was considered even with the spirit and costume already existing, and Pyra & Mythra also had spirits already.
And they still went with Min Min for ARMS when she already had a spirit, when they could’ve went with Max Brass or someone who wasn’t already represented if they were really sticklers for spirits. Yes, ARMS’s director wanted Min Min, but iirc Sakurai was already considering her and maybe Ninjara anyway.
Anyway tbh I don’t really see why the spirits stuff matters anyway, they already seem to not care if a character is a spirit (otherwise they’d be hypocrites) and the main reasoning people didn’t believe they had a chance previously was because the timing of plans, which is the same reason why most people now only think basegame spirits are possible and not event spirits. It doesn’t make much sense for Sakurai, his team, and Nintendo to deny all spirits just because they’re a spirit and not for actual understandable and good factors especially when they’ve already promoted three of them now. If anything, this should still be good news for Porky just incase the ASC actually is supposed to be referencing him somewhat for some reason.