Which is why the proposal was always to have it behind either a runtime of compile time flag. It has never been their plan to unilaterally change the way this works (py2>3 style).
> To mitigate compatibility issues and improve debugging, the proof of concept can run with the GIL enabled or disabled controlled at runtime by an environment variable (or command-line option). If CPython adopts some form of the GIL changes, I’d expect this runtime control to be useful for at least a few releases to address flag day issues.
This doesn't say "GILectomy will forever remain an opt-in".
