My instinct previously regarding FM22 has been to 'skip a year' and stick with 21. I have only just got settled into an enjoyable save and haven't felt any reason to 'upgrade'.
That is, until seeing this dynamic youth rating feature. Hugely exciting, and should make long-term international management saves (and presumably club saves in nations with low reputation leagues) much more meaningful. I'd like to see if there's any other improvements to the international management experience on 22 but given how big an upgrade this could be, I am now leaning towards buying 22 upon release.