Came in to say exactly this. We thought we were 100% migrated to Pro workflows and tools, about a year ago. Still finding random things that have hurdles, such as this.
Recently received a .mdb from a client, they were unable to provide in a different format. Glad I still have good old catalog to use for this... no .mdb access via pro seems like a mis- step to me even if we are leaving .mdb's in the past.