Original Fromme RPO was put in because some Mountain Bikers were acting like assholes. It was also an increasingly small number of spots (less streets) and a growing user base. Some evenings and weekends it was a real shit show up there and the residents (understandably) complained.
Now the latest Covid restrictions are to try and thin the surge of crowds all trying to access the same trail access points. Before they were put in (at least what I witnessed at Hyannis trail entrances) there were incredibly busy chokepoints making physical distancing near impossible. Add to that some of the same bad behavior witnessed when the Fromme RPO happened and it wasn't a great scene.
Seems like the parking restrictions have been fairly effective so far, chokepoints are better. Crowding seems better as people have figured out to ride their bikes in from a few blocks away. Not seeing much bad behavior (Bros with lawnchair beers seem to have figured out to go away first). Until we have a vaccine for Covid, this is the new normal so get used to it.