460s have been known to have issues with humidity
I have owned my pair of 460s since '94, and never once heard that AKG 460s were any more prone to humidity issues than any other mic brand/model. Certainly never had any myself, and I definately have run them in enough humid and rainy settings over the last 15 years to have a good sense of their behavior, at least for my pair.
But, I did have a problem this summer taping MMW in the rain this past June. I expect a tiny drop of water got into one of the XLR cable ends, and that was all it took. Setting up while the rain is falling is harder to pull off than setting up dry before the rain hits. But even a little moisture in the air will cause issues, I have a good friend that had one of his Neumann KM84i do the same thing on Jamcruise this year. I know someone else that had the same thing happen several years ago at Bonnaroo with one of his mics due to moisture.
From my experiences, moisture issues, either strong humidity or actual rain, can impact the connections between the mics and the capsules if you change them in the open in such an environment. But, mostly the issues seem to center on the mic cables. Balanced lines with phantom power on them are very sensitive to moisture on the pins. Even the slightest layer of moisture on the contacts will disturb the integrity of the connections, and the resulting shorting will present itself as hiss and big gain swings.