He is talking about the upload beta that they just released recently. It is a separate minimized window that pops up.In what way? I've been using YouTube Studio Beta for a few months, took some time to get used to it, but the features are still there, you just have to get to them slightly differently. What features are missing?
What do you want it to do? and how do you avoid using it to put a video on YouTube?I don't use it at all. It doesn't do what I need it too.