MDLSITE-6224 we enabled the versions checker to be able to verify if all versions are within a defined interval. This is specially critical under parallel development periods, ensuring that all versions are diverged and overlapping doesn't happen ever.
This issue can be considered parallel to that one, implementing the very same in the upgrade save-points checker.
Note that, in theory, this is not strictly needed because the versions used in upgrade must match the version in version.php, that is already being checked.
But it's not impossible to forget that in some upgrade step, so better we verify all them are within the constraints. At very least the max allowed version must be checked (surely it's not possible to check the lower limit).
Note: Don't forget to update the release process to modify the job each time a new branch is created.