"People" album in Apple Photos not syncing between devices

I've noticed that many of the photos with people on them do not sync that data between my Mac/iPhone/iPad. More research on the forum leads me to believe that it's a common issue and it has been like that for years.

My questions are:

1) with the newest OS versions shown at WWDC, there seem to be some new features with that "People" album - like pet recognition. Is it possible that these updates will also fix the syncing issue?

2) I've spent a lot of time manually marking people on my Mac (adding circles where it didn't auto detect them). If I upgrade to a newer model one day, will I be able to transfer everything in Apple Photos including these? I'm storing all photos locally and in iCloud.