Imo, they've been on a roll lately when it comes to annoying designs. Drafts now bubble up in the UI, so if you start a chat want to finish it, it's all the way the top, regardless of where it started. Threads are similarly broken, if you click on a thread link, it won't link to the new addition to the conversation, just the entire thread. There's also weird bugs or possibly design issues where in a thread, you have limited or not the same options as you have in a general chat window.