Wouldn't they need to, in order to provide this functionality? I use several devices to read Kindle books and it synchronizes my state across devices (latest page turned across each device). The info in this screenshot looks to pertain to that.
Given that kindle devices have different sizes (and usually different font sizes), can be in portrait and landscape mode etc, is "page" even meaningful for cross-device synchronization? Sounds like syncing the text position would be closer to it, not "has advanced a page (whatever page might be)".