The OP is evidence. My phone had it turned on which I think is evidence. Together this feels like reasonably strong evidence but maybe something even stronger is easy to find. Vaguely related: https://markxu.com/strong-evidence
I think both of you had it turned on from past OS installs - it's bundled under other search metadata, the config isn't new to 18. And "it's on and I don't remember agreeing" is absolutely not evidence. This is super common - nobody remembers what they enabled a year ago.
Think about it this way: for people who turn off any & everything that phones home (aka anyone who is frustrated by this new "feature"), the chances of them having turned on something like that upon install is almost nil.
