I've flown a morning CO mid-con at least once a week for the last six months. I've noticed noticed no degradation in quality over the period. I've had eggs with yogurt and fruit every time. I also see no difference in quality from the sporadic morning flights I took during the prior 2 years.

I've mixed in a dozen or so AA/UA flights in there as well - mostly when CO F is sold out (AA F > CO Y). AA meals (at least on mid-cons and breakfast, in particular) are significantly worse.