Windows 11 CO-Release Build 22000.51 is out to Dev Channel

Simple answer is because build 22000.1 was never

flighted to Insiders. We got 22000.51.

Just to correct you, the ISO created from the distribution folder is 22000.1, as was the install. The installation on my notebook was 22000.51 the next day

When I run WU to get first preview I use Wimlib to convert files in \SoftwareDistribution\Download to ISO and using that ISO for clean install give 22000.1, not 22000.51 (I fix that by using other source for creation ISO.)

Simple answer is because build 22000.1 was never

flighted to Insider via W.U.. We got 22000.51 through

W.U., not an ISO.

Edited to clairify

This registry setting does not work as stated in this article which describes (for build 22000.1):

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]

"TaskbarSi" =REG_DWORD:*

; default is undefined, the article says it should be 0 for small, or 2 for large, 1 being like the default, but this does not work for me).

However the following works (sometimes) in my build 22000.51

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]

"TaskbarSmallIcons" =REG_DWORD:*

; default value is already set as 0, changing it to 1 enables smaller icons

Who's right ??? Why are there two variables for what seems to be for the same goal (or different tests of layouts depending on flights?)