One thing I'll say about Legacy XP is Ridley doesn't mean too much in itself. Sakurai marked him as "impossible" in his own interview, which led many to believe he wasn't coming. So removing it cause of Ridley would make things worse. He was vastly unexpected to actually come in Ultimate. Geno is one thing, and some thought he could be base(they were kind of right?).
Now it being removed now might be more meaningful. The timing, imo, has more merit. That said, as pointed out, other companies exist. Could be a case where they discussed what to do before killing it. It's also possible the law on "removing something as soon as possible" has changed so they only need to do so if it would affect them. Removing Legacy XP has more merit now since it's someone like Geno. Ridley, as I noted above, wasn't expected anyway. So it's not like it would've affected sales. People would still want Ultimate more for its own reasons(everybody being back, for instance). On the other hand, maybe someone like Shadow or Waluigi could be coming. Ridley is one thing. But the other three mentioned are significantly bigger deals. Geno wasn't the most expected ever, admittedly, but Shadow and Waluigi were far more, at least in comparison. Obviously Geno is expected a lot too, but being 3rd party and from SE soured some opinions. There's some belief that SE blatantly has been troublesome, but that's not really proven. We lack information, obviously, to be sure on what happened. It's hard to make an educated guess after Hero showed up with significantly more content than Cloud and Final Fantasy have(not just music either. FF has the summons, but that's kind of it. Hero has far more spirits, significantly more other Hero cameos in the Final Smash, as well as music and 4 heroes for alts alone. While obviously the copyright is shared among many owners too, we got more SMRPG content than last time. My theory is that they just wanted more stuff for DLC because it makes them more money, not specifically being stingy instead. Cloud had "everyone is here" so the content is pretty much the same for him minus one costume, and all the 3rd party costumes are being resold anyway for obvious business moola. Well, most anyway. It's possible some were cut, but I doubt it).