Thank you. Third-party doctrine was what I was thinking of. So I'm guessing putting things in your phone will soon be seen as crossing into third-part territory if it hasn't already.
It's not hard to imagine that this kind of automated scanning might be used as an argument for that: "Clearly you had no expectation of privacy for information on your phone..."
Bingo. If you chose devices that aren't open, you're chosing to give away your freedoms. I makes the jump to LineageOS earlier this year because I could see the signs that Apple were getting to comfortable with government. Now, I've got the confirmation I was right in my hunch
https://olemiss.edu/depts/ncjrl/pdf/PrivateSearchDoctrine.pd...
https://en.wikipedia.org/wiki/Third-party_doctrine