Ah. Laws vary by state, mixing and matching manufacturers is illegal in my state, the manufacturer must be on the bottle along with a description. I’m less certain about the expiration date thing, but I believe here they require them all to come back to the same batch in case there’s an issue (including improper storage of the bottle or something)

I’ve been told this is how it works by a pharmacist when they were having trouble filling my rx, and we were talking about controlled substances in particular