Update (10/6/2021) – I just tested the official Windows 11 release today and it appears you cannot bring back the Windows 10 start menu anymore. However the following registry key still works to move the start menu to the left side of the screen.

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
“TaskbarAl”=dword:00000000

As many of you know, Windows 11 will be introducing a new start menu layout. If you want to keep things consistent for your users you can add the following registry keys to your GPO when your company decides to roll out Windows 11.

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
“TaskbarAl”=dword:00000000
“Start_ShowClassicMode”=dword:00000001

The Start_ShowClassicMode registry key will bring back the Windows 10 start layout and the TaskbarAl registry key will move everything to the left like it used to be.