My drywaller installed drywall in the bathroom as we speak and will not tape edges or corners. Has maybe 3 inch holes from cuts and says that they will be covered with thinset upon tiling and grout.
Give me your input on how it should be done. Let me know your thoughts and suggestions. Or is this all normal?
This is just driving me crazy!

What did you hire him for, was he hired to hang, Mud and tape, or is he hired to do the entire bathroom; lay the Tile, install shower bathtub etc.? I think you'll be alright if he is the Guy you hired to complete the entire bathroom as a whole.

If he is to simply do the drywall, mud and tape: I would pay him for hanging the drywall...and get him outa there. You might want to think twice, having him mud and tape. But yes, If he was hired to only do the mud and taping he should complete the project...including mud tape and sand.

I hired him to do the whole bathroom renovation

Isn't he supposed to be taping the seams and edges?

He might be taping and tiling as he goes.

If he isn't on the tile yet...

Yes, all seams should be taped. I assume he will be taping and tiling at the same time.
At this point you shouldn't see any untapped seams that aren't going to have tile place over them.

sometimes they leave the corners untreated that will probably be fine, because that seam won't split the center of a tile.

I always tape and mud the seams. but it's more important to fill all voids to give the shower a tight enclosure yes ,more importantly it gives you 100 % surface glue contact for tile adhesion " better to glue to solid surface than a void

If you find out he doesn't use tape you can request he tape all seams.

This should not be that difficult. Pack in thinset, lay on the tape, and flat-knife to get it set in. In the corners, use a corner knife.

Lol nope he already has some tile up now

In that case I wouldn't worry about it. It's not critical.

I'm worried more about water damage in the future

That being the case, Tape or no tape is not a factor.

The bigger question is, should I be worried of future water damage?

Drywall will not stop water, it merely dissolves. The tape or no tape will not do anything about water. Although a proper job would have been taped.

The issue of water is all in the tile and how it is sealed

Ok,well I'll hope for the best. Thanks for your help guys!
Keep you posted if things occur!

If your worried about the lack of tape (tape applied to the seams) being the root cause for any water damage in the future... need not worry.
Some people do not apply tape.
Tape is used to give seams a "little" more strength.
It is Mesh tape... it's filled with holes.

Relax, allow the man to do his work unobserved.
Better you bring him Coffee and the like ;-)

I think I'm jumping way ahead of myself.
Lol I'll take your advice. Now around the tub, what do you recommend?
I used the denshield, but same idea he says no need for any kind of tape or water proof on corners.
What do u think?