This is not a revision bug, but a sprite data issue that applies to all revisions.

The sprite set it is currently listed in is 16-2.

But the real sprite set for it is 2-9.

Now, Bowser also needs to have his sprite set 16-2...but this is for the switch alone to load correctly.

I am starting to figuring out the boss data, and found this in my testing.

You mean it's listed wrong in the level config listboxes?
Hmmm, that should be pretty easy to fix.

Yes the configuration setting is wrong. I am getting closer to finding the data for the bosses. The one thing that could screw it all up is Bowser Jr. He may load data that is hardcoded. But... There may be a workaround for that. He loads the boss door closing, the screen scroll for the fight...not the 280 loading up to it...and the 276 type left limit. And maybe even putting up the draw bridge. Still working on it though...all theory. Oh, and the zone is in play too. It is set to zero which makes it harder to find .