He returned to Maddox after he was uplifted by Soong, but I can't recall any mention of him after that. Did I just forget something??
Perhaps some of the compatible "Star Trek Online" events? "The Soong Foundation's science team and Geordi La Forge worked to subvert his personality in favor of the 'Data' personality. In 2385, the group managed to unravel the Data matrix, allowing for all of Data's memories, personality and experiences to override B4's. When Data first returned to consciousness, he refused to allow himself to exist at the expense of his brother's life. He therefore created a program in his mind to destroy his own consciousness before it destroyed B-4's. However, B-4 commandeered the program and, having heard that Data was crucial to the war with the Undine, deleted himself before Data could stop him. Data therefore survived in B-4's body. "Through this, Data was able to help the Soong Foundation in upgrading positronic brains and help in the recreation of the emotion chip originally developed by Doctor Soong. Ambassador Spock likened it to his resurrection a hundred and two years previously, though Data likened it more to a return. Meanwhile, a backup copy of B-4 was saved, and thus the science team hoped to create a 'B-4 matrix', and possibly eventually bring Data's brother back to life in a new body. (ST comic: 'Countdown, Number Two'; ST website: The Path to 2409; STO novel: The Needs of the Many.) "In 2409, Data entered a highly secure room where he activated a positronic circuit on an identical android he called 'brother'. (STO short story: 'Unexpected Honor.')" [Memory Beta.] Memory Alpha also notes that "the 'Guardians' story in Strange New Worlds VII dealt with the Horta culture being transplanted to the planet where the Guardian of Forever resided. The Crystalline Entity visited the world almost a thousand years after the events of Nemesis and described an encounter where it was forced to destroy B-4."
Hm.....I prefer what happened in the Cold Equations trilogy. B-4 does not have the capacity to understand how someone is vital in a war, or what self sacrifice means.
The first Picard trailer had a disassembled android with the same face, didn’t it? So it may be that B4 was taken apart by Starfleet and/or the Federation.
The painting scene, yes. But the scene in the first trailer gave me the impression it was an actual meeting.
Holosimulation maybe yes. It just didn't have a dreamsequence vibe to me. Then again, it was very short, so we'll just have to wait and see
Which gave me the impression that it may be B4 given when Data copied himself to B4. As to a dream sequence, it did not seem like such to me especially given the android parts in the drawer.
Data did not copy himself into B-4, he copied his memories into B-4. When he uploaded Lal's memories into his own brain, he didn't become Lal. He just knew what she'd known.