Well unless we want to get back to the style of writing where every little thing has to be explained to the audience in excruciating detail for it to be "real" and we cannot trust audiences to pick up on anything....I think we take this at face value.I mean, sure, you don't hare John Delancie if you don't want the fans to think it, but actor choice isn't in-canon evidence.
As you said, you don't bring in John Delancie if you don't want your audience thinking Q. So the audience....is going to think Q. Ergo....its Q until proven otherwise (which at this point would be dirty pool by the writers imo).