IIRC, the quote was popular during the Dutch Revolution but it may have the earlier roots: always hard to tell with the popular slogans.
As for the similarities with the Byzantines, yes, the Ottomans kept Bulgarian diocese completely subordinated to the Patriarchate of Constantinople. OTOH, IIRC, Russians suspected the Greeks to be the secret Papists (which did not prevent them from using services of the Greek patriarchs, when needed). Can’t tell up to which degree this assumption was correct but candidacy of Sophia Paleolog had been, indeed, pushed by the Papacy.
But, this being said, who in practical terms could provide an effective military help to the crusading cause circa 1470? Matthias Corvinus had limited resources, even if he is joined by Vlad Tepesh. Anyway, he made peace with the Ottomans to be free to fight against Bohemia and Hapsburgs. If we change that, would the Hungarian-Bohemian-Hapsburg military alliance against the Ottomans realistic and sustainable? After all, there were mutually-contradicting interests.
Burgundy? Charles the Bold seems to be a suitable type but he would probably demand a royal title as a compensation and his generalship was not of a highest quality. Not to mention that he would need to get there and somehow communicate with the personages of a higher rank.