As not-uploading VTIMEZONE has both pros and contra, and uploading VTIMEZONE has also pros and contra, the most reasonable step would be to offer a per account/global option to the user “Shall VTIMEZONE data be uploaded?” After a while experimenting with this option, more information and experience can be collected.
It would be a further improvement, if for servers returning DAV:calendar-no-timezone in OPTIONS on a calendar-home-set, that option is automatically enabled.
RFC 5545 was written in 2009. Today operating systems have built-in knowledge about about Olson database. When the timezone is both not in Olson DB but widespread, e.g. Europe/FLE, then it is still in the VCALENDAR.
As long as Morocco continues to change its timezone rules on short-term, users will experience “unexpected” shifts.
If the proposed change, that is a matter of fact in effect, has led to negative feedback for DAVx5, I guess this would have been already taken into account.
Compare the discussion of “May the CUA not send the VTIMEZONE data, when the server would strip that information anyway?”, to the discussion “What do you think about CUAs, which insists form the users to provide a user name and password, in order to complete the CalDAV setup, but never send the credentials to the server, unless the server returns 401 Unauthorized, and the server may never return 401 Unauthorized, if it offers both authenticated and not authenticated (anonymous) CalDAV access?”