The only issue is ATM. If ATM says yes to the PAC 16 (which they have explicitly said they had no interest in doing), then Utah gets left out. Any other scenario puts Utah in.
Is the PAC 12 with Utah and CU more modest than a PAC 16 with those two teams plus Texas, TTECH, Oklahoma, and OSU? Of course. But the only scenario where Utah stays in the MWC doesn't involve Texas and Oklahoma agreeing. It involves ATM having a massive change of heart and turning down the SEC to join the PAC 12.