I've found Twitter fandom to be a better gauge of many things than what critics say, what "hardcore fans" say, etc. A lot of cases of people being angry get written off as "over-reaction," making things up, or "wanting to be mad," but my experience is that those tend to be just a means of brushing off complaints instead of taking the time to look deeper into them.
Disclaimer: none of the above is stating a position any which way on the very specific topic being talked about right here. I haven't read enough of it, and probably don't have enough info on the history with Jean and Emma anyway, to really weigh in on this one. My comment above is about Twitter matters in general.
There's a reason people that work at Marvel feel like being on Twitter, and further, why they use it to discuss their work.