I will say, I am a little surprised that some BA regulars aren't defaulting to the "well you can always drink in the lounge before boarding" argument, since they do often go the "well you can always eat in the lounge before flying" argument when the topic of substandard CW food is brought up.

Back on topic, as a regular AA and CO flyer, I do think that pre-departure drinks should very much be a necessity in all premium cabins, including CE, if for no other reason than the fact that it adds to the perception of premium service.

I should add that if you are looking for a model to emulate, go with CO, not AA. AA FAs will almost never serve PDBs on short/mid-haul domestic flights in order to speed up boarding and ensure turnaround times are met. CO FAs will always, religously, serve PDBs even on short hops like IAH-AUS, while somehow ensuring that turnaround times are met, and boarding is even more orderly than on AA.