Except at this point, acceding to fan demands would be doubling down on the very mistake they previously made on the production of the movie itself. They’re in kind of a tough place on that point.
Their best course of action on that front is to stop making themselves available to fans on that level so that way they’re not beholden in an ugly way to whatever fandom’s whims might be. With that concern more-or-less removed from the table (however long that might take) it would be easier for them to do these sorts of things without it seeming like a response or capitulation to outside pressure. Basically - every other studio simply does these sorts of things because they want to do it for their own internal reasons.
Tangentially, this is probably part of the reason Warners hasn’t pursued a “Snyder Cut” for Justice League (only part, and probably not a very big one) - if they ever announce that, it’s going to be seen as validating a section of the fanbase that’s been seen to be very ugly about what they want. Aside from the fact fandom whims are fairly fickle and not well thought out in many cases - Hollywood producers have a thing about control, and they like to appear like they’re maintaining it. Things like this imply they don’t really have it, and that implication is not one most people at the studios would prefer to nurture if they don’t have to.
The Sonic case is interesting, but I also think a big part of it has to do with Paramount being a studio that is in a terrible position (it’s barely a major at this point) and eating the amazingly bad buzz the trailer created THAT early wasn’t a great option. The Deadpool case wasn’t so much fandom getting the job done as it was savvy producers (Reynolds/Miller) taking advantage of a studio regime change to build buzz for a project via “leaked footage” that was already most of the way there. It’s more like they used the fandom to get what they want rather than the studio organically responding to fandom pressures.
I think best case scenario are deleted scenes on disc 2. I don’t think there’s going to be an extended cut, mostly because I don’t think Abrams ever planned on doing one, didn’t really want to do one, and nobody at Lucasfilm seemed to be entertaining the notion that one would be possible. Or would need to be possible. That studio especially is probably pretty jumpy at the notion of post-release alterations being applied, for reasons that are pretty obvious here. In order for one to be made, they’d have to be working on it now for an as-yet unannounced double-dip release (which certainly wouldn’t be done in time for the Skywalker Saga set, I don’t think) and I don’t think anyone involved really wants to even mess with The Rise of Skywalker anymore. Pretty much everything said in the past two weeks by anyone who worked on that film seems to be just… angering everybody.
Besides which, Bad Robot has more or less moved on, and are a Warner Bros. affiliate now anyway. Lucasfilm, in that case, would have to essentially handle any “extended cut” business themselves, without Abrams - and that’s a whole 'nother can of worms to consider.