I'd back city to be able to flog you off to another club for nothing too. Or, all they'd then do is release the player immediately. So many loopholes
Yeah could totally see that happening: Williams doesn't want to mutually terminate his contract, freeing up the remainder of this contract with Melb City, Man City just 'purchase' Williams and then Man City can terminate the contract they have with Williams. Melb City have just gotten around the salary cap, Williams gets the remainder of his contract and free to pursue his career elsewhere - win, win for CFG and Williams, not so much the HAL.
This could have huge implications. City Football Group under the guise of Melb City get a lot of decent players under multi year contracts - though only pay them enough to fit under the cap then Man City purchase the players and pay the outstanding fee negotiated with the CFG.