[pier25]

It's much easier to simply use this with whatever date you prefer:

    defaults write com.apple.SoftwareUpdate MajorOSUserNotificationDate -date "2030-03-03 12:00:00 +0000"

[egb]

I've got that in place and still get the Tahoe popups, so there's some other mechanism here.

[nottorp]

Confirming. I tried that several times and it never sticks. Sequoia here.

[testing22321]

Same for me.

I setup a focus for do not disturb that runs from 12am to 11:59pm every Day.

Have not seen the popup on 4 weeks since I set it up