This level of pointless conservatism frustrates me.
I got to play around with it a bit. The only thing they simplified is the main toolbar [1].
Everything else is mostly shades of grey, icons and dimensions.
A developer could upgrade to this and nothing would change.
And yet, we have complaints about a "dumbed down" interface, that is wasting space [2], that JetBrains should "fire their design team", ...
I'd love to see the age distribution of people complaining here because I personally had been hoping for this update. Design must be a balance between conservatism and progress and JetBrains nailed it in this case.
[1] They even show you the shortcuts now, which you should have been using anyways.
[2] The vertical space from the top of the window to the code is the _exact same_.