I have attended a Mozarabic Mass - still have their booklet - in Portugal.

Their "Major see" is just a normal Latin bishop who doubles as responsible for the Mozarabic Mass.

Then some priests offer mozarabic masses as special events to keep the local tradition.

It is not much different from the usual Latin mass - somewhat different order of events, some texts are very close, some different but you can still follow the parts of the mass as usual.

I think supressing it was the right move. It would be too much hassle and confusion to have 2 similar rites in the same territory.

One trouble they have is the old saints calendar. not just the dates are different, but also no saints from the last centuries have a mass written for them.