Earlier quoted context omitted.
Nobody's reported seeing that sort of network traffic sent off of iOS devices. It's trivially easy to spot it, and it's well documented, going to Google and others across the web, though.
On my iPhone, Safari browser history synchronization to iCloud was enabled by default.
https://support.apple.com/en-us/HT202303
Is there any evidence that Apple is lying, and is actually decrypting them somehow and using them for advertising purposes, rather than for the "coherence" feature?
I don't actually want browsing sessions to be unified across devices, so I do wish that it was turned off by default. (Though being able to close tabs remotely is a sort of interesting capability.) However, it doesn't seem to be actual spyware used for advertising or tracking purposes.