We flew CUN-DFW-SFO on 12/15 and as usual CUN had no problem with liquids. I've had to empty water bottles for them but they have always been very lenient with meds. I was carrying cough syurp and inhalers (for the 4 kids) and had to dose at least once en flight. I won't need to test going home (SFO-DFW-CUN) as we've exhausted our most excellent Mexican cough syrup (that you can't get in the US).

But as you know, in Mexico the rules are really just suggestions.