I've got a bridge to sell you.
I do remember very well the outcry when Blizz announced to have SC2 split into 3 games.
If Blizzard just said "Okay, listen, one main game + 2 expansions", people would have said "Oh that's cool".
But some people do get very sentimental about these little things.
No. They would still be pretty pissed off that their favourite faction's campaign was dumped into an expansion. But then again it's Blizzard. They have enough lemmings to buy anything they make, so they don't really have to care about some fan backlash.