No, actually it’s quite apt to invoke St John Fisher for this matter. He would not have agreed with taking part in Vatican II’s false ecumenism because prior to Vatican II it was condemned.
(Talk about a tautology.)
I think he'd appreciate the assistance of allies who wanted to defend marriage. And that's what the conference was about: not denying doctrines, not merging un-mergeable faith communities on the basis of ambiguities and platitudes, but defending Marriage: which is a matter of Natural Law even before it is a matter of Canon Law.
A good man is not a perfect man; a good man is an honest man, faithful and unhesitatingly responsive to the voice of God in his life. - St. John Fisher