I get magic because my daddy is a devil is okay for that magic to be divine, but I get my magic because I learned it from a devil means the magic is somehow occult? On the surface, that doesn't feel right to me.
Now if they say something like "devils and fey lords teach witches occult magic in order to disguise their influence", I could buy that (assuming they explained how a nonoccult patron can teach occult magic [for devils I assume it would involve mining knowledge from occult casters souls in Hell]), but I haven't seen anything like that either (especially on this thread)
The real question here is, what exact are we expecting witch patrons to be? All we know is that they'll be concrete beings rather than nebulous metaphysical concepts, with Baba Yaga being a single example. But we really don't know what else.
People are assuming that we'll see fiends, celestials, fey, and great old ones, based on how 5e warlocks are implemented, but considering the core differences between that and pathfinder 1e's witch (spontaneous cha caster vs prepared int caster), are those assumptions really valid?