I have no evidence why a priest would say to withhold that information, but I can think of several, one of them being the priest has no clue about Canon law. and given that Canon law, like civil and criminal law, is a specialty requiring three years of training, that is no stretch. I can think of others, and I choose not to sidetrack this discussion.
But the individual directly impacted by the matter would be the spouse, so what the spiritual director said might be worth pursuing before the tribunal. And spiritual direction, as opposed to confession I do not believe to be protected by penittent/confessor rules if received outside the confession.
In any event, the defective consent is primarily upon the wife, and secondarily upon the husband. If the spiritual director is not competent to determine the depth of the SSA, it becomes irrelevant. And the question on the Husband’s part involves a matter which the Church says is objectively disordered; so part of the issue is to what degree the husband suffers from an objective disorder.
Again, one question no one seems to be addressing is why the husband married if he has SSA. Is it his objective to use her as a foil? That does not sound like the makings of a covenant relationship. Depending on the depth of his SSA, it may be that he is not capable, within the understanding of covenant, to give himself to her.