It could be related, but that comes from the desktop section. It doesn't say anything about Enhanced Synk in the Android section.
Although, if you go back to the 51.0 release notes, it does say "Improved reliability of browser data sync".
https://www.mozilla.org/en-US/firefox/android/51.0/releaseno...
> Enhanced Sync to allow users to send and open tabs from one device to another.