I don't miss BG1&2 menus and BG3 UI isn't final - UI takes a lot of time and iterations since things constantly change and require rework. I don't expect to see a final version of the UI before the final stretch of the development and til then I won't mind the current look too much.
To be honest though the DOS2 stuff definitely doesn't help to get rid of the DOS feeling the game has (though I don't think it's fair to call it DOS3). Especially since it just keeps your mind on all the DOS-gameplay stuff they ported over with little success.
I hope they will make a more dedicated effort to move away from the over DOS-estethic to something more DnD related. No need though to go back to 90s-UI design.
