Most PUP's are either mounted to a scratch plate on F style guitars or mounting rings on G styles therefore none of those are screwed into the body. Only exception I have seen is on P & J Basses where the rear J PUP and split P's are screwed into the body.

As I am soon to start on a tele kit too and also saw Adams vid screwing neck PUP into the body and wondered why would you do that when there were adjustment holes in the pick guard. Mind you I have seen some tele's where there are no neck PUP adjust screws visible and these have probably been screwed into the body and would a right proper pain to adjust. Wouldn't it be simpler to mount to pick guard so that adjustment would be simpler and easier? Doubt there would any difference to the sound.