I like that idea more than the retcon of him being a prototype prior to Data or Lore that real Soong, dream Soong, interactive hologram Soong, and android Mrs. Soong all failed to mention to Data during his interactions with them over the years of the show.
His mom mentioned them. Why isn't that good enough? It sounds like she's talking about B-4 exactly in Inheritance, actually.
JULIANA: But... how do you know the same thing won't happen? Creating a stable positronic matrix is very tricky -- your Father lost several prototypes before Lore.
DATA: I was not aware that he created any androids before my brother.
JULIANA: There were three of them... they were like children to us... losing them was very painful. When Noonian decided to try again, I was very much against it. I didn't think we had the right to bring a life into the world that had so little chance of surviving.