After the second round of the Masters, Koepka said he probably wouldn't have defected to LIV if he had been healthy at the time. He went for the guaranteed dough because he wasn't sure he'd ever get back to his top form.
So he's not exactly the best spokesperson or example for all the wonders of LIV, and IMHO he's the most likely to return to the PGA Tour as soon as his contract would let him do it.