Thad -
UK airlines have been after the level playing field for years. Many of the more mature airlines are being very responsible under the new regs. Few moans and groans on the new longer FDP in the morning and lack of early / late regs which has meant more common sense rostering.
Most of the mature airlines are also protected by scheduling agreements.
Plenty of science also being used, airlines with CAA approved frms having commuting protocols to manage commuting. I suspect also UK AOC's will be leading by example for where the new regs are not so good.
Yeah there will be rogues unfortunately so I agree with your concerns but don't tar all the UK AOC with the same breath