As for Rayman, there's many ways to make an amiibo work.
Even having his hands/feet slightly attached to his body, but positioned in a way it looks separate, can work. Also, I'm always weary of taking things from Twitter as confirmation/deconfirmation. Companies can be highly segmented, and support team might not know one way or the other. Same with that community manager who works on Minecraft--she would probably be out of the loop if something were to be happening. Heads of companies, though, they would probably know.
I'll be holding my breath honestly until we find out who the next two fighters hopefully are at E3. Really hoping they'll be worth the wait and anticipation. Also just really interested in seeing what games we'll get to see at E3 this year. Looking forward to Pokemon's Sword and Shield Direct next week, definitely a game I want to get when it comes out. A full fledged Pokemon game on a home console? Heck yes.
I would think we're probably only getting one fighter announced at E3. Makes sense. #2 - June, #3 - August, #4 - October, #5 - December. Doesn't have to always be two months a part, but shows it's a manageable time frame spread out, and also has a two month leeway from the final deadline. Could be June, September, December, February for all we know.
Also, I'll admit to being disappointed in what we're seeing from Sword and Shield (so far). First main game on console, and it feels like a backwards step from Let's Go--barely indistinguishable from the 3DS games, only higher res, from what I've seen. I hope the Direct proves that wrong. Going to miss all the improvements made in Let's Go.
EDIT: Re-watching the trailer, it actually does look better graphically than my initial impression back in Februrary--though I still prefer the vibrant color palette of Let's Go to the more muted colors of Sword and Shield. But my main issue is what I feel the gameplay might be like--I liked a lot of the improvements of Let's Go, such as Pokemon in the overworld, etc. Makes me wonder what other features won't be in Sword and Shield.