Is there a way to call wusa.exe to uninstall a Windows Update within PSADT? Or is there an alter ego to Install-MSUpdates?
You can try:
$KBID = "12345" Execute-Process -Path "wusa.exe" -Parameters "/uninstall /KB:$KBID /quiet /norestart"
See the examples at the bottom: https://ss64.com/nt/wusa.html