Silence is a form of consent, particularly for someone in authority, such as a bishop. So Novus Ordo bishops who do not condemn Vatican 2 are thereby consenting to it. In order for any of them to not consent to Vatican 2, they would have to publicly repudiate it.
To answer Vermont's question, there were only a couple of bishops with jurisdiction who did so, and refused to consent, even by silence. Abp. Lefebvre is the most well-known example. I believe Bp. Castro Mayer did so too, though I don't know very much about him. Bp. Thuc publicly condemned Vatican 2 and denounced the false papal claimants as anti-popes.
Those are all the ones I'm aware of, and since only public rejection of Vatican 2 can overcome the public presumption that they consent to it, it stands to reason that we must necessarily know who publicly rejects Vatican 2, and since those are the only ones I'm aware of, most likely that's all there is.
There were certainly cardinals and bishops who privately did not accept Vatican 2, but since they did not publicly condemn it, by that omission they thereby publicly accepted it even if privately they didn't.
We don't need to hear them specifically talk about their thoughts on Vatican 2 to know whether they consent to it or not. The absurdity of this is made clear if you substitute a different bishop and a different council, and say the same thing. For example, to say, "I don't know what Cardinal Spellman thought about the Third Council of Constantinople because I believe he never spoke publicly on the matter, so I can't say whether he accepted it or not. For all we know he may have had reservations about it." This is absurd because every bishop is presumed to accept every council of the Church.