Thank you. I have suspected that, but I prefer be sure rather than take something for granted and made a mistake.
I don't read Batgirl (for now), so I failed to understand what you meant, but your comment doesn't contradict mine (at least I don't think so), in fact I think the way a character is perceived and treated by the story is related to the role he plays. I didn't write: «…how she faced up and overcame the problem of her paralysis…» for nothing, but exactly because the way she was treated by the story made her great and she was treaded in that way because she became Oracle: if a character doesn't have a role in the stories, he simply disappears from the book. So I think that keeping for Barbara the identity of Oracle, even if she no longer needs a wheelchair, even she is act like a batgirl can help to maintain her anchored to her past, not like a victim but like a survivor who overcame the adversities of her life and this can make her stronger, greater. In other words I think the identity of Oracle can act as shield at the same way you suggested for the wheelchair; the two things can be used together.