I flew LAX-JFK in late July and sat MCE 12D. The girl across the aisle ordered a glass of wine and the FA charged her. When the FA turned to me, I mentioned that MCE was supposed to get complimentary cocktails and she said, "No, only Exec Platinum."
I actually pulled up the June 5 email I had received about "complimentary drinks in MCE" and showed it to her. She looked shocked. She said, "I didn't even know about this." She went away, talked to the head FA, came back and said, "You are absolutely right. I'm so sorry." and then had to refund the woman across the aisle (who thanked me). I was, however, in the row just behind bulkhead so don't know whether those folks got a refund.
I recommend having a screenshot of the email on your phone to show FAs (without needing WiFi to pull up the email itself).