It has happened before. Parker lost SEC POY to Fowles (LSU went 14-0, Tennessee 13-1) but Candace took home the majority of the POY awards that year while Fowles didn't win any.
In regards to players being predetermined POY, I think it's a valid concern as of late, with last year being a good example. A lot of people felt Victoria Vivians was robbed of SEC POY, as she put up great numbers and her team dominated the conference. A'ja missed 3 games and her squad finished just 11-5, yet she still took home honors over Vivians. I thought KLS, Vivians and A'ja all had POY caliber years and should've split the awards, but A'ja swept everything.
To Ionescu's credit, she has had massive games against ranked teams and is having a stellar season. I don't think anyone can argue she doesn't deserve it at this point even if it's bothersome that it feels like a foregone conclusion.