I just ran into a case where the father(90) passed in June of 2020.   They CPA at the time instructed the bene(daughter) that no RMD would be required under the “new” 10 rule.   I remember something about that during that time, but obviously now, if the owner reached RBD, RMD is required.   The daughter has not been taking any RMD and is just now asking if she should have been.

So, was there a window pre 2.0 where that was true and would it apply to this case?  Or, is the daughter 3 years behind on RMDs?  Assuming they took year of death RMD, if not, then 4 years behind.