Curious if anyone has seen or heard anything on this front
Unfortunately not.
3 PvEs in a row with no new character is long. Nearly a month.
It’s saved me a bunch of HP, at least.
Next event should have someone new. Fury was the “new” one last event, so they’ve managed to be pretty consistent alternating a new release in every other PVE. I’m guessing we’ll see someone (probably that “B” X-Man) next event.
As the number of potential lazies slows down, though, we may see a slower release schedule.
As a minimally pay to play player, I’m ok with waiting awhile for a new character. I just now finally got all the covers I needed for the Torch man! Still don’t have what I need for Panther and Psylocke. So although I like new characters, I also like being able to actually have all the covers I want! 
I’m in a weird doldrum where I only have a handful of 3*s with full covers, but none of the ones I need are rewards for any events. I’ve just been logging for daily rewards.
Seeing as how Beast had a major role in Xmen, Days of Future Past, my money is on Beast being the new character. Bishop was in the movie also, but Beast had a much more prominent role. Of course, if the devs were in a generous mood, they could give us both Beast and Bishop. 
I still want to see them mix up the way they release characters now and then. Have a mega-event with three new characters. Add four new ones of various rarity straight to tokens only with little to no notification. Other things I haven’t thought of.