Think this is a security update. HTC had issued a security patch to many 2011-2012 phones.
As for Jellybean, HTC told me that they are still reviewing the Rezound for JB. So we are in the waiting game for that.
I dont think we will see it anytime soon and if it comes, it wont be until June-July.
They also mentioned that they are now reviewing all devices that came out last year to see what gets JB but they did not say that it wasnt going to get it.
We shall see.
By the time it comes, I have a feeling, like the Tbolt, many will jump ship.