No. We saw that once Harry said screw winters law the back is broken. So it wasn't healed completely. I argue that Michael may have healed it completely in skin game while wielding uriels Grace. Michael did lay on hands to help Harry against nics wife.
So I'm talking about a healing that goes past winter.
It isn't an illusion though, as in it's all in Harry's mind.. Severed spinal cords do not work that way.
We have woj that winter isn't really into healing. So it likely is that what mab did is an approximation of healing but she can leave Harry paralyzed without her ongoing magical support.
I believe she did fix it, it was part of the agreement for him to become Winter Knight, it was specific ergo, she couldn't go back on her word... Have to go back to what was originally agreed to to see. Now if they agreed
as long as Harry remains her Knight his spine would be healed, then when he said screw Winter, she was free to re-break his spine. However if they agreed simply that
in return for him becoming her Knight she'd fix his spine, there is no way she could get out of the bargain without serious repercussions.. No, Mab isn't into healing for the sake of it, but to get what she wants she'd do it... So when Harry's legs turned to noodles when he said screw Winter, I think it was an illusion.. If Harry pressed her on their bargain, her come back would be, "see, where would you be if I hadn't helped you? Remember our deal..."