BitPay also dropped Central Texas Gun Works on a few days ago.
That's a business that is fully legal at both the state and federal level so there's no gray area involved. It does show you how "regulatory soft power" works though. Something doesn't need to be illegal for it to generate regulatory problems for a business (or their bank).
They might have their own rules about who they work with, but the fear of being prosecuted is always there and they're probably not willing to take the risk with dispensaries.