As far as I can tell, their model even seems to include, for example, any installs on a different system that I might do of the Unity-based game Cult of the Lamb I already bought—months ago when it launched and when Unity had a different TOS. And that’s bad news for the devs because Steam’s terms of sale allow me unlimited multiple installs anywhere I have Steam installed, as long as they only run one at a time.

But even if Unity doesn’t try to go that far, it would absolutely apply if I did a second install of a new license I bought after 1/1/2024 on EGS, or if I got put on Game Pass and I did a new install from that somewhere I didn’t want to install Steam.

And since Unity apparently uses click wrap agreements upon opening their dev tools to set licensing terms, using the tools to make a patch afterwards would likely include new terms that subsequent installs of the patched version will now be counted for existing licenses, even if the original deployment wasn’t under those terms.

That led to Massive Monster’s response that they’re going to be delisting Cult of the Lamb entirely.

As far as what you quoted, all this says is that they won’t use their historical telemetry data to retroactively bill you for installs performed before 1/1/2024, and that any given install will only be charged for once. But multiple installs by the same purchaser are still charged multiple times unless Unity agrees they’re all on the same system.