I think Ichigo is in Aizen equations ...
All Captains went " Wtf you're strong Ryoka "
But Aizen goes " was I too soft ? "
Ok there's some large power gap between them but ... Comon' Aizen is a mastermind no way he could rule out such a huge X factor.

Aizen got Ichigo's party into his plans
And he is the one talkin about Shinigami/Hollow
Could Ichigo and/or his familly an experimentation of Urahara techniques ?
It would explain why they can see holowand ghosts ...
Why Ichigo could have broke Rukia's Kidou
Why Ichigo got this IchiHollow within him
Death of Ichigo's mother could have trigger all this ...

60 & 61 makes Bleach's plot a lot more entropic and I'm sure everyone is pleased about that