It's likely that once the virus becomes endemic, it'll also be mutated to a less lethal form. Eventually, basically everyone will have had it and built up some level of (probably incomplete) immunity, so community gathering restrictions will no longer be needed to reduce load on hospitals.

As far as timeframe, probably 20-75% of the population will have had it by the end of the year. Certainly by 12 months from now. Or a vaccine or anti-viral will have been deployed.