I’ve been on Tahoe since last year. Everything works well. Its highly unlikely anything will break.
They aren’t even ads, really. They’re place recommendations. And they’re anonymized. Its no different from someone having a sponsor in a YouTube video. Additionally, you can very easily just ignore said recommendations by not tapping on them and scrolling right past them.
You do realize they are going to do it anyways? You’re one person out of billions of Apple users. You’re in the minority of people who actually care about these sponsored recommendations. And I don’t think spines have anything to do with “rejecting” something Apple is going to add regardless. Are you seriously going to stay on 26.4.1 until the end of time, over anonymized recommendations? The security issues that have been fixed outweigh getting sponsored place recommendations in the search tab.