Bletchleyite
Veteran Member
I doubt the London-Birmingham services will. It's not a very long journey. Best guess, there might be a couple of vending machines.
It may well be that they standardise across the services. Avanti West Coast has catering on the Birmingham route despite not really needing it just because it's the same as all the other routes including ones with journey times well in excess of twice as long.
Certainly the Glasgows justify it.