I was in a rental car this week and pure accidentally (1 in 1000) hit “yes sync contacts.” Didn’t know how to reverse/revoke that decision. Wish I did/could
It probably helps that this isn't exploited often. You're fine. To attack someone requires so much effort the clickbait article didn't deserve the views.
Additionally: if you were a person travelling for an abortion, not in your car because your state is all fucked up(!), can the cops request copies of texts you've received/ sent?
Yes, if they have probable cause sufficient to attain a warrant.
Or they ask the rental company nice enough for a few monutes they may not even need that, as a prosecutor would argue that you waived 4th Amendment protections by not taking sufficient measures to "ensure your privacy". Third Party Doctrine.