I have a December domestic longhaul (not one of the existing "premium" transcons) booked in F. 5-hour flight during breakfast window outbound and dinner window on return. When I booked it said "refreshments" but I noticed in booking that it's been changed to "Breakfast" and "Dinner." Not sure if that signals the return of something hot or is just their recognition that what's on offer now is indeed becoming permanent.
Supposedly hot meals return 11/10, bookings after that date now list breakfast/lunch/dinner rather than refreshments. I don’t know if any details have been released regarding what the new hot meals will be.