If no proof is offered (in either direction), then the proposition can be called unproven, undecided, inconclusive, an open problem or a conjecture.

Stating that you don’t think that it’s possible is irrelevant. It’s either happening or it isn’t. True or false. P or ¬P.

is extremely unlikely to be true in my opinion.

Is an argument from ignorance. Not trying to be rude, but this is basic logic.