Things you can pass on to your friend:
1. Travel trailers are not just dead weight being pulled behind the tow vehicle. On average, 12 - 13 percent (could go up to 15 percent) of the trailer weight is being carried (tongue weight) by the tow vehicle. Thus, the tow vehicle must have both, towing capacity to pull the trailer, and payload capacity to carry the trailer's loaded tongue weight, in addition to the weight of aftermarket accessories, people, pets, weight distributing hitch (about 100 lbs), and cargo.
2. Look at the tire / loading sticker for a max occupant / cargo capacity. That is the weight capacity that Tahoe has to carry everything listed above.
3. At 10,000 GVWR, that trailer could eat up to 1500 lbs of payload. Quite likely, that Tahoe would be maxed out on payload, before he adds people, pets, accessories, or cargo.
4. Looking for Tahoe's max tow capacities, the highest I found was 8400 lbs.
5. That truck / trailer combination would be a very unpleasant (likely unsafe) towing experience.