So now people want vague title card announcements years and years before there's literally a single thing to show them?
Ok...
Yeah, people have clearly been okay with that.
After Metroid Prime Federation Force, Tanabe did hint at Prime 4 coming. Sure enough, it was at E3 2017 as a title teaser. That same E3 we also got Samus Returns (honestly if they just had that and not Prime 4, I think people would have been okay with that).
People were really excited about Bayonetta 3.
Bethesda talked about an Elder Scrolls mobile game this year, and said they were working on ESVI right after that, but it won't be ready for years.
If they had to announced a Diablo mobile game, people would be okay with them showing a title card for Diablo 4.