Seeing as you're already running OpenCore Legacy Patcher, would you really be affected by them "killing" support for your machine? I guess getting official parts/repairs seems to be what you'd lose. Maybe you could stock up on the most likely to fail parts ahead of time. I'm sure third party repair shops would still be able to fix the machine even after Apple gives up on it, though.

Ultimately they will stop supporting x86_64 arch so even Open Core Patcher might not help you at some point.