I did a bit of googling, and as with all things in life, it looks like it depends alot of factors (your age, amount of weight loss, age of implants, skin elasticity, etc...)
But from what little I have read, the three main complaints of massive weight loss after breast implants are (1) skin rippling around the implant (2) implant dropping lower due to loss of fullness, and (2) your new smaller size makes the implant look too big for your frame, and look disproportionate.
Since the implant itself does not change size, I would guess that you would not suffer from the tube boob look, so that alone is a good thing, lol.
Can you reach out to your original surgeon and ask for more info?