To be fair, I think this really is the Nash equilibrium of options Bio could choose from.
No matter what they were going to anger someone. But, as I have said many times before, I am of the opinion that the more creative freedom they have to expand and build from the better the story will be and the better the game will be. Having to choose a canon ending is a bit too rigid. Having to go with IT is a bit too rigid. having to follow the ending of ME3 1:1 is a bit too rigid. In this reboot-esqe game, we essentially can just have the "there was a great war a long time ago and we won" line and then go from there. In addition, we can have antagonists that are equal to or possibly even greater than the reapers...who knows.
I, for once, am intrigued.
See, I am not angry, not even sad, just kinda let down I guess. I get it why they did it and I get it that it truly is an interesting premise its just the bad taste of ME3's ending is going to follow that. I can't help it, I truly loved the games but all that is left now for the new one is "oh well..."
The worst part is that the developers are probably going to make something good but because of the bad legacy left for them by the previous guys there is always going to be a thought in my mind "so where are they going to screw me over this time". And I am probably not alone in this.
Also I would absolutely, truly hate if they pull another "unbeatable" enemy crap. For the new enemy to be worse and stronger then reapers they basically have to make a space-lucifer riding in a space ship that can alone on its own destroy planets with one shot. Like a cross between devil, death star and that transformers sentient planet thing.