I've said before - I don't get the animosity towards robes, or the complaint that they all look the same/boring. There's as much variation in them as anything else, and I absolutely expect my mages to be in robes most of the time, just like I expect tanks to get armour.
As to the idea of them not getting Healing gear? I doubt it. If we're taking 5.3 and the term
apothecary as hints, then that (for me at least) is absolutely compatible with the image of a potion brewer in robes.
The one existing thing I can immediately think of in-game to suit the idea is the
Ramie Robe, which never seemed quite right for any of the other mages but I think it would work well for a potion-maker.