Since MDEV-27279 mysql_upgrade only really runs when detecting major version upgrades, only checking the first two components of version numbers.

There are two problems with this though.

#1 this is not really mentioned in the release notes, they only have:

{{* prohibition running two upgrades in parallel (MDEV-27068, MDEV-27107, MDEV-27279) }}

All these MDEVs where handled by the same commit, but the commit was not exclusively about parallel upgrades. MDEV-27279 definitely was about something completely different

#2 when running mysql_upgrade after a minor upgrade it now shows:

This installation of MariaDB is already upgraded to 10.4.22-MariaDB.

There is no need to run mysql_upgrade again for 10.4.24-MariaDB.

You can use --force if you still want to run mysql_upgrade

It is not clear from that message that the reason for this is that the major version did not change, just the minor (point) version. Not knowing about the MDEV-27579 change it rather looked as if something had gone wrong in the version string comparison logic.

This message should definitely mention that it's caused by seeing the same major version, e.g.:

This installation of MariaDB is already upgraded to major version 10.4 (10.4.22-MariaDB).

There is no need to run mysql_upgrade again for 10.4.24-MariaDB as it is the same major version.

You can use --force if you still want to run mysql_upgrade