Its not compelling upgrade at all. Not only for those with 2018 but for everyone. Why? You may ask.
Its simple, those that needed the ipad got the 2018 already and those that were waiting until now are most likely ok to wait little longer as this update proved to us that Apple has something juicier coming later and hence this "gap stop". Kuo has said it and other leaks/rumors point towards it too so yeah Fall is the time when we will get (most likely) the real upgrade. If not then march 2021 but that is probably unlikely. Recently, Kuo has been right pretty much most of the time and so were the other leakers so given this "nonsensical" upgrade its pretty much almost certain that fall will be what we were waiting for. Better chip, better display and finally better aluminium I hope