It looks as MBF, but I would like someone more experienced to give advice.
The transitions policy is here: https://wiki.debian.org/Teams/ReleaseTeam/Transitions
We do not have automation to rebuild packages and file FTBFS bugs, do we?
Automated whole-archive rebuilds have been done (see e.g. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=768691 ), but I don't know whether they are done regularly.