Sidebar popout gone?

I was on the fence about the sidebar in Edge, liked being able to open music streaming and websites inside Edge, but could never keep track of which instance of Edge it was running in.

Then we got the ability to pop it out and dock it on the edge of a monitor.   Game changer, made me a huge fan of using it. 

Now I noticed with the latest dev build that is gone.  Is it just me?  Is it coming back?