Merging blocked for the `main` branch

I’ve started seeing that PRs are showing “Merging is blocked”, even when all checks have passed, is this something deliberate where the main branch has been marked as protected?

See Mailman 3 Blocking the main branch due to too many buildbots failing - Python-Dev -

The branch was blocked to find time to unblock the buildbots.

Ah, I missed that. Thanks.