This is absolute bullshit and not at all how it works, now or back in the 1980s.
Nah, it's absolutely how it has worked since the 1980s. You've never owned the game, just the physical hardware it's on and a license to use the game. Go read any manual or back of the box or actual cartridge or disc.
So if the developers of a game go bankrupt, or a single developer of an indie game dies, what do you suggest happens?