Well I am stating a philosophical fact, not an opinion. The position of 'not holding any metaphysical view' is called agnosticism ie "not knowing". That is fine and no one has has definitive claim to know the answer.

However the claim that "all metaphysical beliefs are delusional" is simply untenable. If someone is a philosophical agnostic, then they likewise cannot make claims to either support or deny any specific metaphysical views.

Well that's not what I am saying. I am however being more specific. If someone for example asserts a view that "there is no evidence for the survival of consciousness after death" then they are stating that they do no believe there is any substantial support for such a view. Stating an absence of support for something however is not the same as stating an affirmation of the opposite. If someone where then to make a further metaphysical claim that "consciousness definitely ends at death" that is simply their own metaphysical view which can be labelled materialist-nihilism, and that view would need to counter the apparant evidence for the existence of survival of consciousness after death (ie near death experience reports, children with past life memories etc).

Thus as I said, unless one is a true agnostic with no views on these matters at all, one inevitably will take up a certain metaphysical position and this is as true now as it was in the time of ancient Greece when all the major philosophical positions today were still extant.