I also encountered this issue and filed a report in Feedback Assistant, FB7634016.

I may have found a solution to my most pressing issue but I think it only reinforces my other questions. Out of desperation I clicked through to see the generated headers for CSSearchableItemAttributeSet and, unlike the documentation which is in alphabetical order, the header has .htmlContentData and .textContent right next to each other. That gave me the idea to try a query string of textContent == "someSearchTerm" and now it seems to work! Although I'm grateful for this, it raises more questions for me because I only assign to .htmlContentData but yet I have to query "textContent". How can I figure this out in the future without blindly guessing?

While we're waiting for 15.2, can anyone tell me if they also see this behavior? I've still got a client on 14.x who sees the "Add people" option and can send an invitation via iMessage. However when I click on that invitation in iMessage on an iOS 15 device it tries "Retrieving..." and then says "Item Unavailable: The owner stopped sharing, or you don't have permission to open it.". If I copy the link and open it in Safari I see "iCloud has stopped responding." and inside the details "ShareRecord: Unable to find applicationIdentifier for containerId = [my container id] and fileExtension = undefined" among other things. I'd like to try and understand this issue is related to the other iOS 15 issue and I should wait, or whether I need to be tracking down a separate bug.

I independently reproduced this issue before I found this thread using the final Xcode 14.0. I found that my UIHostingViewController subclass was able to modify the status bar style by implementing the .preferredStatusBarStyle property if the hosted SwiftUI View just contained a Text, but as soon as I wrapped that Text in a NavigationView it no longer works. Checking the "Debug View Hierarchy" confirms that the whole view hierarchy changes pretty significantly just by adding the NavigationView inside of the View inside of the hosting view controller. One difference is that in my testing even setting .navigationBarHidden(false) did not restore the ability to change the status bar style. Opening the same project in Xcode 13.4.1 and running in iOS 15.5 simulator the status bar style changes as expected. The suggestion from @taxiboatdriver is using iOS 16-only APIs so I don't think that is a solution for my app that's targeting iOS 15+. If anyone else has any solutions I'm still searching...