It depends on the cue supplier/maker. Most of what I have seen, use just a straight tenon and the ferrule has some longitudinal ribs down the inside with a small hole in the bottom.
Glue is applied and then the ferrule pressed on.
I have come across some that were threaded, but these were only a few.
Maybe some one else may comment on the US market, but this info is quite accurate in the NZ market.
Neil