I have done further testing and have found that the airport / gate are irrelevant. I used KIAD gate B26, KATL gate 7 and 12, KSNA gate 8 and 10, KLAX, etc, etc.
The problem is aircraft specific. the aircraft that state "catering service not available for this aircraft are:
(keep in mind some are obvious but I wanted to be complete)
Beach 58 (default)
Beach350 (default)
CRJ7 (default)
Lear45 (dsefault)
C172 (default)
C208 (default)
DC3 (default)
EMB-135 (Feel There)
EMB145 (Feel There)
EMB 120 Brasilia
I can use the above aircraft at any gate, any airport with catering service unavailable for this aircraft
Obviously some like the c172, B58 I would expect a catering truck not to be available, but the CRJ7 and Embraer's I would expect services.
The Feel There 175 and 195 both work as well as the Majestic MJC-8