We can have both. Yabu will get his scale salary, while Ojeleye can get either the minimum or whatever is left of the cap space after the Hayward signing. What he can't get is the money Yabu is getting, since removing Yabu's hold before the start of the season would require Yabu to agree to it, which I find very unlikely.
Personally, I'd rather have Yabu here (and don't care either way about Ojeleye). We took him at #16 for a reason, and now it's time to give him a chance to show us what he can do. Playing in China for another year won't teach him anything