Who, other than children, do not know this yet?

Their parents, new/casual games, charity shops that might want to resell, etc.

It just slaps a big bold 'haha the fuck you isn’t even in the fine print anymore’ label on a product and makes our cyberpunk dystopia a little bit more obvious, but doesn’t achieve any useful goal in terms of altering actual game design/support or consumer rights.

True, but that would make it slightly easier for offline games, games that allow for private hosting, and games with an end of life plan that would allow it. They would be able to compete more easily if they could be easily identified. That could then incentivise companies to add end of life plans.

A step in the right direction would be great. Even if it’s a small step.