Babs needs to walk again
In the world of dc comics where just about anyone can come back to life and most wounds heal almost instantly, it makes far less sense to me that Babs is still paralyzed from the waist down, than if she were to somehow regain her mobility.
Also, she's proven herself a great leader throughout The Birds of Prey. With the use of her legs she'll remain a leader and she'll be able to get out in the field. There's potential for stories having her face where she's more useful: as Batgirl or as Oracle. Barbara has more tactical options that way. Cassie still needs to be a around.
Personally I'd be happy with Richard as Batman and Barbara as Batgirl, and they can live happily ever after as the new Dynamic Duo (and letting any offspring of Bruce's not related to Selina disappear into the retcon realm)