Yes. I think Kaaya won't be really appreciated until after he leaves. That's just do to the ignorance of the fans thinking that be it a freshman QB or one of the current backups will step in and have better success than Kaaya from day one. Unfortunately this will be one those, "I told you so" moments and what's even worse is that I have to sit through these "growing pains" with U! SMH
How do we know someone won't step up and be better next year? Room was superior to Dak until injury. Bledsoe was better than Brady. Winston won a championship as a true freshmen as soon as he got a chance. Nobody knows what we have behind Kaaya until we get a chance to see.
So you've chose two examples that work for your argument when the opposite is true of almost every other case ever. Backups tend to be worse, period. I don't know if Allison will be better (and I hope he is) but I'm pretty sure we will be much much worse with Rosier at QB. So whats to lose from having Kayaa back for another year. It can only help us.
Having said that, i'm not sure he gains much more from being here for himself.