I'd like to bring up a counter to your point in the disclaimer about Microsoft and Sony characters, you say that you don't want to see Sony or Microsoft characters until all the Nintendo stars we need. Something I would just like to say, Smash is still a Nintendo crossover first and foremost, allowing in 3rd parties is something that makes sense, cause a lot of them are a part of Nintendo history, but adding Microsoft and Sony characters are what you would call Smash finally jumping the shark, seeing as Smash is meant to be a crossover between Nintendo games, adding Microsoft and Sony would mean that Smash has lost its way.
Just my small thought on some stuff said in the disclaimer.
But like you said Master Chief doesn't belong in Smash, he maybe an icon, but is still a 1st party Microsoft character, which is why he isn't happening.