I don't quite follow you. Especially when you say "Those you got an extension in march have a 2022 review date"?
Under normal circumstances, your review date could never be more than 12 months in advance. The extensions earlier this year were handed out on 1 April (not March), and if we assume review dates are randomly distributed throughout the year, then at that time, most people would have had a review date some time later in 2020 (with perhaps 25% or so having review dates in early 2021). Surely after getting a 12 month extension, most of those people would now have a review date in 2021, rather than 2022?
The VA email seems to make it clear that the "take one flight by 28 March 2021" offer is applicable to those people, as long as their new review date is in 2021.