We can certainly get 4, I'd say any less is a disappointment. Of those 4 listed I think Olejnik is most likely to not AA, based on how uninspiring several of his matches (particularly as of late) have been. Still, he should AA.
As for who the 5th will be, I'd go with Teague Travis. No easy road to do so, but he's certainly got the ability. Same goes for Brayden Thompson if he's got enough in the tank. My first guess might be Jordan Williams if not for the injury(s). Not sure he will be or can stay healthy enough to make AA this year.