Looking at their playlist, with them also playing things like Madonna and Cyndi Lauper, they pretty much have become an even more variety hits focused station than what originally was more oldies-ish.
Their recent skyrocket in the ratings is why I think 96.3 really will stay Simon. Entercom is probably starting to feel a bit of the sting from Earth on both Magic and Classic Rock 101. So a variety hits station that skews a little older may be the buffer they need.
If you've listened to Chuck at all lately, they play a good deal more 2000s-today they used to. And mostly 80s and 90s so it has a younger skew.
However, 96.3 is surprisingly weak as a station. I used to think X98.5's strength was bad. But 96.3 appears to be even weaker.
So all that said, I'm not sure it can do much against Earth. But it's still the right play IMO.
There are rumors that it will eventually go to an Urban format, but really, what will that do other possibly take Hot and JAMZ down a bit? B93.7 beat Hot pretty good last book.
I just think they would have a more vested interest in protecting Magic and Rock 101. Neither of which are doing as well as they once were (especially Magic).