we had a traverse a few years ago. i didn't come with a tow package but with an add on hitch it hauled my 2500lb boat like it wasn't even back there.
When i looked into upgrading everything it became a cost issue to tow our TT. trans cooler is different, fuse box is different due to lack of brake controler wiring, no tow haul mode ect. its a $400 option to get the tow package but its a couple thousand after the fact to upgrade. Its cheaper to get one with the tow package. Theres alot of info if you google "traverse tow package". Ours was a lease so it wasn't worth it to me. with a tow package they can haul 5000lbs. without its significantly less.