I have heard that too but it doesn't really make sense. Fat is what triggers the bile and I don't think the body can differentiate between olive oil fat (gallbladder releases bile) and coconut oil fat (gallbladder doesn't release bile??).
If the tried and true method works for you, then I would say keep doing it. For me, I don't think I can swallow the olive oil/lemon juice mixture ever again so I use something I can get/keep down.