I guess I can sort of see the loss of Oracle, but then again I think it's also interesting when characters change and become something different. If Barbra has been in that wheel chair for 10-20 years whatever it's been in real-life since the Killing Joke then I say it's time for something to change to make her different, her regaining her ability to walk and re-entering a Bat-life is interesting. Especially since they didn't just de-canon TKJ, Barbra is still dealing with the PTSD from that event and now survivor's guilt from getting her ability to walk again.
And, as I said, I really enjoy her as a character and her inner monologues. She's just a fun, care-free, flirty character. I like it.