I don't think that's so strange.... as far as I know, the NL is the only league left in all organized baseball that still has the pitchers hit, so I'd think most pitchers would come up to the Majors without a professional at-bat..... could be wrong, of course.....
It's not quite that clean, but pretty much, yes.
In double and triple A ball, when both teams are NL affiliates, the pitchers bat. In the Pac Coast league, both NL affiliates have to agree to have pitchers bat, but both have to agree.
In any minors game with an American League squad - no pitchers bat.
In rookie, single A, and all other leagues, no pitchers bat.
So it's not odd that an American league pitchers first AB is at the major's level.