The possibility to install an add-on is an option to get the classic GUI back - one that doesn't add to the download size of the program and more importantly, that doesn't create noise in the code base. Maintaining one small feature seems easy but they accumulate.
In my personal opinion offsetting a few KB of extra download size with perhaps years of system resources lost to run an extra add-on makes no sense for something that has been there all along. Not to mention that removal of the 'status bar' required the addition of a new bar to hold Add-Ons, the code to overlay the link preview on the URL bar is far more complex than a single status label, etc. The status text removal made the code more complex, making it a draggable element would have been peanuts extra. Not saying it applies to every case but this one was about as simple as it can be.
