I will boycott if this happens.
why
I don't like Rayman for whatever reason. His aesthetic displeases me and his games are mediocre platformers (uh-oh) in my opinion. If they chose Rayman as a third party rep instead of bringing Snake back, or picking a cooler third part rep... that would be unfortunate.
But, seriously, I wouldn't boycott. I'd still buy 3 copies of the game like I was planning. I would just prefer anyone else over Rayman.