I know this is not what you're asking, just another point of view here, and a non-expert-in-this-field one at that (plus, I'm not in your area). But if I can help it, I'll never empty my pool again (long story). I would do whatever it took. Cover the pool. Vacuum it every day after work is done. Lower it just enough to perform the tile work. Clean up the mess afterwards, whatever. Especially if the finish is old-ish. "Tile guy says pebble tec not at risk..." What does he know about it? Is he going to pay for any repairs? Or replacement? The water is part of the structure of a pool. In a perfect storm, you relieve the pressure the water is applying to the finish, especially in the heat, for a week, and that can compromise the finish. You definitely wouldn't want to do that with plaster, and PebbleTec is composed of plaster.
And you're assuming the job will go well, no material issues, no flaking workers, no delays, etc.
The "tile guy" doesn't want to get wet, or do extensive masking or bending over or any extra work, great. It's not his pool. He'll just give you a blank stare and a shrug if there's a problem. At the very least I would call PebbleTec and have them weigh in on this before you drain. If they are 100% OK with their product being dry and exposed like that for a week or more, then I'll be happy to admit I'm wrong.
And if emptying is the only way, then I'd arrange with the contractor that that be done in the shortest time possible. Prep, prep, prep, drain, cut out the old tile/copoing/deck, then fill same day. Plenty of pools get the deck, coping and tile done after they've been filled. It doesn't need to sit empty for more than a day (IMO)...
My apologies if I'm out of line (or dead wrong). Just want to give you something to check on, instead of relying on the tile guy about this...