Henadic Theologian
Legend
Why would it be? That's what we are seeing with Eberron and Astarions.
Eberron is races that had their focus on Species of Eberron origin, even if a few like Changelings & Shifters found their way elsewhere. Astarion's Dhampyrs is directly related to him being a vampire, it's related to a specific theme, they didn't add in Hexborn & Reborn to it.
Genasi have become a very important part of FR lore, especially Calimshan so an update & expansion there makes sense, but otherwise I think it will actually mostly be NEW species. Wemics, Shades, Saurials, maybe some stuff we don't expect. Maybe Tabaxi get a reprint because they are Forgotten Realms in origin unlike most of the MoM species.