The main case where I think a grace period may be warranted is any currently in flight PRs (especially those from external contributors). (I am assuming there are some open PRs, since that concern was raised above, but I haven’t specifically checked
how many there are myself)
Saying “no new PRs on this topic until a PEP is approved” is one thing, shifting the goal posts for already in progress changes is something else (it may even sometimes be an appropriate step to take, but having the main branch JIT include a few merged PRs that aren’t present in Python 3.15 isn’t going to meaningfully affect the PEP discussions, but abruptly halting pending PR reviews has an immediate negative effect on the contributor experience)