I happen to know people who are working in/with airline caterers. All catering firms have cut staff, many have workers on part-time schedules. There is no issue whatsoever to prepare food as pre-Covid. In one station, they currently prep for 3 carriers. Two of them do full F & J-service (as reportedly LH/LX do as well), one is in cold food/sandwich mode. Typically they get the overall monthly schedule 2-4 weeks out. Final adjustments (add, cancel a flight) are usually within a 48 hrs window.
They have workers on call to serve those last minute changes. Crew meals are like pre-Covid, some now are ordered for cargo-only flights as well, e.g. crew-only, no pax catering.
Many of non-working staff are prepared/very willing to come back to work, so there would be no issue on the production side, if/when airlines are adding flights or go back to regular/pre-covid catering.
There seem to be no government restrictions on the production side, e.g. situation is similar/identical to restaurants preparing food for take-out, if not served on premises.
Bottom-line: this ball is in the airline's court, not the caterers.
(Not to discount your thoughts, EWR764
)