It is annoying. I hate scaling toolbars, etc. on the side (or bottom/top) of the screen that follow me around when they're something I have absolutely no interest in. It makes sense to utilize it for people that want it, but is there a button I can click somewhere to get rid of it?
That button is not, in fact, an intended new feature. It is a bug - something that apparently accidentally got turned on as part of the server tune-up work that, while paused momentarily, will be ongoing.
So, please consider the button to be akin to our occasional downtimes - an inconvenience that'll go away when the maintenance is done (unless, of course, we see that folks are using it and like it, in general, in which case maybe it'll stay).