I think it would be a mistake to do a blanket extension of everyone for another year - essentially giving people status in 2022 for flying they did in 2019. Who knows if people who were HVF 2+ years ago are still in the same jobs, whether their companies will want or need them to travel as much, etc.?
I think a better plan would be a soft landing plus a Q1 2022 challenge to regain or retain status. Their status could even be extended during the Q1 challenge. If things get largely back to normal by the end of the year and you're still not flying in Q1, then the airlines probably don't need to extend your status longer.
At least on AA, elites are prioritized by spend though. On the other airlines, people who earned status each year in 2020 and 2021 could behind those who haven't set foot on a plane in 2+ years for upgrades.