[cjsuk]

That only happens if you tick all the boxes in the app store preferences window. And that's not the default. So you had to tick it.

[intoverflow2]

It is by default I'm actually sitting on a fresh install as of a week ago on my work machine.

It probably retains a legacy setting if you updated but this is straight from Apple. I never even knew that preference box existed.

[oneplane]

It will actually both make a notification popup on "turning on automatic updates" which then directs you to a settings panel where you manually have to check the box.

[cjsuk]

Mine is a fresh install of the same vintage.