It also has the other footnote: **On flights with full drink service. The number of drinks served may be limited. That gives the FAs a lot of latitude in deciding who to serve. There have been various reports in recent months that some FAs make up the rules sometimes, with one even telling a passenger that alcohol isn't a benefit in MCE. Others state "the limit is 2", though I guess they can even say the limit is one given that footnote.
Ah yes, that would be annoying and unfortunately kinda typical for the inconsistency in service on American. IIRC the "free drinks in MCE" is also written on the seatback card with the drinks menu and IFE information, maybe something you could point out to the purser. I've only flown short flights since return of full drinks service and as such never really had more than a drink or two, but those were never really a problem.