Ryujin
Legend
So what do we know so far?
Data is dead, his appearance is a dream sequence
Nobody ever says Data's daughter's name, Lal.
the Daystrom Institute still exists
Synthetics became more common place at some point
Synthetics went bad and burned Mars
Synthetics were banned, yet at least one works in StarFleet Archives
Picard has a storage unit to keep his old stuff
He kept the Captain Picard Day sign
Maddox is in hiding, probably made the new Lal-alikes
Dahj-Mom hasn't called the other daughter out of concern
Romulans work for Picard and his vineyard
Romulans have a thriving Scrap business
The Federation turned its back on Romulan Refugees
Some neighborghoods on Earth aren't as smurfy as others
Picard isn't used to running up stairs
Also, that the synthetics weren't on-par with Soong leval androids. I suspect that will figure into why they 'rebelled.'