For those who are running 12.1, the EOL is 12.2-RELEASE + 3 months, which translates to mid-January 2021. Hopefully the transition to 12.2 is smooth as usual.
After freebsd-update(8) to 12.2-BETA1 I could not start X11 because it was yelling about missing /dev/dri/card0 device …
The solution was to remove DRM kernel packages:
# pkg delete drm-*
… and build them again from up-to-date /usr/ports tree against 12.2-BETA1 /usr/src sources.
Now 12.2-BETA1 system without any other changes booted with X11 fine.
… but I am keeping the 12.1-RELEASE ZFS Boot Environment just in case :)