From a business perspective, it allows rhe companies the time to consider the cost implicarions and sell the game at the appropriate price.

For instance, a companynthat sold lots 5 years ago and has minimal players now and would be required to refund everyone as they close would kill the conpany.

Future releases, they can add self hosted or community hosted servers as part of their code structure. They dont have to activste them until late in the game cycle.

Hopefully that becones the norm and more and more companies allow it, similar to how some allow modding. It can solve a bunch of gaming problems. Safer servers for kids. No obsolescence. More fine tuning of game settings.

Part of the fun of the first network games was their customisation options. It was more open and thus seemed like there were more possibilities.

A big issue could be technical debt.

It takes work to prepare something for "other eyes"

I'd hope for some effort from game devs that give a shit about keeping thier work alive. But for a "finished" game to go back and do the work could get tricky.

Yes you could just release docs and info but it's not that easy sometimes.

Depends on the wording but a game sold after January 1st, 2027 could also be a five years old game that is still sold.