There is a screenshot of the opt-in screen in the article. There is no default, just two buttons to say yes or no.
I swear, outrage should only be allowed based on the amount of work one is willing to put in before expressing it. If you don't do the reading, you don't get to be publicly angry. It'd save us all so much trouble.
For the record, the feature was always optional, as per the original announcement. Presumably the change is it is now part of the setup flow where it was going to be a settings toggle instead.
Which is, incidentally, how this used to work the first time Windows had this feature, back when it was called "Timeline" in Windows 10.