Yes that's another important point, the training departments will struggle just to get furloughed crew back to currency, if this goes on end of June, which is very likely, just to get thousands of crew into the Sims, will be a massive task, the Sims was already full when running staggered standard recurrent training,
There will be serious lack of trainers and Sim slots. One Sim can maybe run 5 sessions in a 24 hours period, providing everything runs as clockwork, that is 10 crew a day, that will take some time to get rid of that backlog.