Unless working on accessibility features will directly bring Reddit money, it's safe to say that they won't do so. If they can guarantee that every member of r/blind will become a paying customer (rather than a non-paying user), they'll make a move. Until then, expect nothing. It's the same as dealing with any business about accommodations - unless there's a visible opportunity cost that offsets the accommodations, they won't do it. The ADA and local authorities serve as the cost to brick-and-mortar businesses (they might get fined for more than it takes to just do the accommodations; or they might get shut down), but there's no such recourse on the internet.