Looks like we are SOL. I don't broadcast much anymore but if their new chat isn't robust I'll probably find another solution for my broadcasts. I'm not IBM's demographic anyway. Once they bought Ustream I knew the writing was on the wall. I enjoy engaging with my viewers and using an IRC client over web based was so much more convenient. All of their documentation on their new "White Label Chat" (Custom unbranded chat) indicates chatting via IRC clients will not work. It specifically doesn't say it will not but I'm not to hopeful. The wording of the following statement I found in one of their docs seem to say "IRC Chat" will no longer work. Although their new chat does seem to utilize the protocol.
"Here are some of White Label Chat's highlighted features
Ustream accounts are no longer a requirement to log into the new chat. You just choose a nickname and you should be able to participate in the discussion.
No longer Flash based
Newly created channels only see the New Chat and not the IRC chat.
Existing channels have the ability to switch from IRC chat to the New Chat manually until Aug 31, 2017"
The fact that they use term "IRC Chat" indicates to me their version will not support it.
Oh well.