I see Metroid Prime 4 being brought up as an example.
Take a look at that game. Nintendo could have said, we are working on a new Metroid game in an interview like they have said before, but that doesn't appease anyone. No one believes them until they show a title screen.
If Bethesda had their conference and showed off Elder Scrolls blades like they did and didn't show ES6, but later said in an interview that they were working on it, would anyone believe them? No. They would look at and see most recent games are Oline MMO and a phone game. There is no reason to not believe they haven't abandoned the core single player game.
So it's to shut up us gamers. And yet as soon as they announce it, we continue to not shut up.
I mean hell, I feel Ben Affleck wants to quit being batman solely so that people quit asking him about batman every single time they ever see him. He could be interviewing for another movie and half the question will be about batman.