I didn't think Read was likely to be more than a fringe type when I saw him in Potomac a few times, but that was before he hit a bunch of homers (relatively) for a catcher in AA. Defense was ok in all respects, not great or bad in any area, so he's not a classic defense-first backup type.
Strangely, his offensive numbers seem to be getting better each season since Hagerstown, even as he moves up, which is a great sign. I wouldn't think he's a candidate for OD next year, but I could always be wrong. If the organization thinks he's the prospect, not Severino, it would make sense for Severino to keep the bench warm in the majors and see if Read can continue to improve offensively.