What happens is that core seems to be upgraded to Matomo 4 code. At that point it does have the code already for Custom Variables 4.0
But then in https://github.com/matomo-org/matomo/blob/3.14.1-rc1/plugins/CoreUpdater/Updater.php#L170 it seems there is still somehow automated information as when I upgraded to Matomo 4 the CustomVariables plugin was automatically disabled for some reason.
So this PR aims to fix that when upgrading from 3.14.1 to Matomo 4 the Custom Variables might end up deactivated.
I'm not even sure how things work in general. I would have expected before that disable plugins code runs that somewhere all the plugin information is being updated. Like how does it know the information of the updated plugins in