I think you handled the phone call very well. I can't remember if you have gone to any alanon meetings yet? I think they would be such a comfort to you. The meeting I went to had three parents there.
I don't think your daughter has any ill intent towards you. She called. That is what young adults do - call their parents. Sometimes just because they want to hear their voice, sometimes because they want something, whatever. If you handle all her phone calls with such grace and clear boundaries she'll know you are there for her if she decides she'd like real help with her drinking - or anything else.
When I was your daughters age I drank way to much. It was alcohol abuse, dangerous, and I had real consequences. By some miracle I did not become an alcoholic. They'd call when I had a house full of blasted drunk people and I know they were freaked out and worried. They did not give me money and they did not except that kind of behavior in their home (I didn't live at home but I visited) but they were there for me and we maintained our relationship and for that I am eternally grateful. Of course, there wasn't Facebook then so all my stupid stuff wasn't plastered on a screen for them to see.
I think you are really smart to maintain your boundaries regardless of whether she is an alcoholic or not. Her behavior is unacceptable and not in line with your values and she'll look to you for that kind of guidance, even if she doesn't admit it. I did. If blocking the graphic details of her behavior from your Facebook page assists you in maintaining a relationship with her, then I think that would be an important thing to do.