I suspect that the mid-term for service will be pre-wrapped meals and that the long-term will still mean that everything is pre-wrapped and served to the passenger on a tray which the passenger then unwraps and serves. Much of the time consumed for F and J is in plating the food and in Y from removing covers.
I have no doubt that many service reductions are close to permanent because the economics of commercial aviation are not going to recover for 3-4 years.