I think it would be a good thing to call if you wanted to. Of course, like Zed says, you don't necessarily want to be "Hey! I just heard you were gay! We should get together!" as that may be misconstrued, and besides, there's probably other things you could catch up on first that would help ease the environment.
But, yeah, I say go for it. Having an understanding ear is always helpful, and if you can provide that, do so!
