> Of course things change.

Except they don't. The clients are frozen in time forever. There's no change happening here. It doesn't matter if they should be changed, they aren't being changed. Printer firmware does not get updates.

> New attack vectors are discovered in protocols and need to be fixed.

IF that ever happens, which is super duper unlikely, then kill it since the clients are unfixable. But this is not an ongoing cost. There's no continuous change aspect to that at all.

> New devices with new capabilities are created and need API integration.

That's not change, that's new features. As I said, simply tell those things to go do their own thing. That's unrelated to leaving Cloud Print on life support.