Yes by not playing you surely tell blizzard to provide content for a game they've stopped developing content for. -.-"
Diablo 3 will be kept alive simply the way that Warcraft 3, Diablo 2 etc currently are.
All one can hope for is a blizzcon reveal this year for a new diablo installment with some real effort put into it.
That said, I like diablo 3 for what it is, but if I want a real fix for my ARPG (as its apprently now called, still remember when this was hack n' slash....)
I'll play PoE, Grim Dawn or even Wolcen for now