Currently Amtrak has 9 snack coaches on the roster, with 1 that seems to be out of service. As far as required services I believe they only need the 1 on the Heartland Flyer. So I would think keeping two cars dedicated to this service, as they seem to be doing now, wouldn’t be a big deal.
As for demand, with the newly expanded consist, the CCC potentially has to serve meals to over double (on 421/422 days) the sleeping car customers, in addition to cafe service to two additional coaches (now 5 on 421/422 days and 4 on the others). Even before ridership and the consist had picked back up, I have witnessed very long lines for the cafe window, even outside of the very busy STL-CHI corridor. So I don’t see how the demand wouldn’t be there.
Plus the time window these cars operate in does cover meal times.