[jholman]

If I'm understanding you, some or all of these questions are explicitly addressed in the Q&A. My apologies if you got that far and I simply didn't understand you.

For example, your first question seems to be asking about whether there's a semantic change coming from a lack of immediacy in when __del__ will run. And the answer is explicitly "yes, and the docs already told you not to count on that".

As for multi-threaded Python code... and perhaps also multi-threaded C code in extensions... I think the clear answer is "yes, our whole goal is to remove some guarantees that were previously provided, so if you counted on those guarantees you're in trouble". Again, c.f. the Q&A in case that helps.

From the talk, it doesn't look to me like Larry Hastings has a plan for the policy change in question; so maybe "bridges that need to be crossed once [the technical issues are smaller]" is correct?