in my cultural context a cock block is when somebody is trying to hook up with someone and a third party (or, more loosely, event etc e.g. "I was going to go see your dad but that tornado warning cock blocked me") and I think that trying after someone specific in the first place is a necessary component in a way that "health class birth videos traumatized me so i'm not interested in hooking up with your mom" wouldn't qualify because the initial interest was never there.

if your understanding of the term is different then this has been an uninteresting linguistic disagreement instead of a mildly interesting philosophy thing. ¯\_(ツ)_/¯