Fans understandably have a lot of questions about the new timeline where Ben is alive and at the academy, and, with The Umbrella Academy season 3 still not starting production, they may be waiting for answers.
When the brothers return to 2019, Ben is the number one and leader of the Sparrow Academy. This could suggest that Reginald was unaware of Ben’s role in The Umbrella Academy.
This could mean that once Reginald Hargreeves ruled out Luther, Diego, Allison, Klaus, Five, and Vanya, the number of children he was able to adopt was reduced and the odds of Ben being chosen were so slim at The Umbrella Academy.
It could be that Reginald Hargreeves couldn’t resist adopting a boy as powerful as Ben. It could be that Reginald could see the potential in babies and was inevitably drawn to Ben, as powerful as he is at The Umbrella Academy.
A theory from The Umbrella Academy indicates that he was Sir Reginald’s favorite. If she had no reason to reject Ben, it would make sense for her to identify him as a strong candidate for the Academy once again after he was born.
If the logic is accepted that Sir Reginald did not know everything about the future, it could be that he did not view Ben as corrupt and dysfunctional, unlike his adult brothers, as he died before proving to be a disappointment at The Umbrella Academy.