As others have said, unfortunately, with AP becoming a prix fixe character meal, there is no longer any fine dining at WL. As others have said, your closest signature is Cali Grill at CR, however, it may be difficult to get a reservation there last minute. Definitely see if The Wave at CR has availability. Again, just a boat ride away and it's one of the best casual TS at WDW, IMHO. You could hop in a cab/uber/lyft/Minnie Van and head over to GF - Citrico's typically has reservations available (I would double check on the
MDE app before heading over) and it's very good. If you would rather stay at WL and AP and Whispering Canyon aren't to your liking, check out Geyser Point (mostly sandwiches and salads, but lovely, outdoor atmosphere) or Territory Lounge (limited menu, but it's typically quiet inside) .
Just to clarify, Whispering Canyon does have AYCTE skillets on the menu, but most of the menu consists of a la carte options. It is not exclusively an AYCTE restaurant.