abirdcall
(she/her)
Why would a divinitation wizard get a weapon mastery. But I bet each class will get a "martial subclass" at one point with weapon mastery incl. . Although it will make your game even slower, your problems with the feat are kinda pulling in different directions.
I don't think they will. Valor Bard and War Cleric didn't get it which I take as a firm design decision to keep it away from full casters. I could see a weapon focused Monk subclass getting it but only because they aren't full casters.
I also don't think they will be starved enough for ideas that they give up and start adding it onto the new subclasses because they haven't come up with anything else.