Just watched the match. First things first there are a number of risky spots during the match and of course, Becky and Charlotte took about 10% of them with the Kabuki warriors taking 90% of the risky spots. At least 3 or 4 times Asuka was sent head first into piles of chairs which isnt much better than taking an unprotected chair shot to the face.
When it comes to Charlotte's Fallaway Slam "into the barricade" that causes Kairi's problems, she tries to do it from 2 or 3 yards too far out. That creates a high angle when Kari's body just about hits the barricade before the floor and she has a nasty twisted landing. When I first heard about this I heard that she fell on the exposed concrete but I don't think thats the case, still the bit of padding on top of it is where her head falls as far as I can see. I'd say its more the bad landing from a sudden drop that causes trouble for her.
Kairi barely moves and a referee walks over and checks on her after about 4 seconds while Charlotte walks away.
When Charlotte goes over to untie Becky from the ladder, Asuka runs up and delivers a normal chair shot from behind. However perhaps Charlotte was surprised by the impact because she very clearly yells "Oh feck" facing into the camera.
We then see Kairi walk over and she stumbled several times, before then standing straight and screaming at the crowd. She dives at Becky on the ladder and looks like she takes boots to the face, but I'm pretty sure she hit how she was supposed to and it looks worse than it is.
Charlotte slaps her across the face, its not that bad obviously much worse if your opponent potentially has a concussion. But Kairi has taken hits 10 times that in Stardom, where she has also been concussed before.
Whether she was concussed, or the barricade spot just took a lot out of her physically when Kairi dives off the apron to try and splash Becky, she has a Becky-level non-jump and just plummets compared to the leap and height of her normal Elbow Drop. So something seemed up. She barely makes the table and of course it doesnt break
Soon after standing her legs give way and shes on all fours.
Kairi slams Becky's face on the chair and then falls down. At this point she doesnt seem to want to be out there anymore, there's nothing on her strikes on Becky on the floor and she seems to be talking to Becky on the floor back and forth.
Kairi again goes to all fours then just lays down prone. But 2 seconds later shes encouraged to get up for the next spot as far as I can tell, perhaps by a referee? As I can hear "come on... "and then something but I cant quite make it out.
Then comes the messed up Spear. Flair runs and grabs her, I'm guessing Kairi was supposed to jump and bump for the impact but instead she just goes down lightly. Again, it looks like she has nothing else to give physically. Flair slaps her on the floor, looks pissed off, goes straight into powerbomb position and yells "Move this" as she throws a chair off of a table thats already set up.
Kairi looks frightened half to death as Charlotte lifts her up, again with no spring from Kairi herself. I'm gonna say I think its half her selling the danger of the spot in terms of her facials there, and obviously half not looking forward to taking even more damage in the match. She starts to hit at Charlotte's arms as she lifts her, I dont know if that was to make it seem slightly more realistic or if she really really doesnt want to get powerbombed at that point. But she almost doesnt seem able to use her core and sit her top half up into position. And Charlotte powerbombs her... And its just a tad over the normal intensity that someone would powerbomb someone through a table on the outside. Its certainly not an impact that is going to help Kairi out regardless of whats wrong with her.
Asuka buries both opponents under tables and chairs and goes to get Kairi for the winning stretch. But Kairi is laying on the floor, clearly upset and probably crying and saying she cant do it. Asuka lifts Kairi to her feet gingerly and tells her to keep an eye on becky and charlotte
Charlotte gets back into the ring and holds a chair above her head like shes about to waffle Kairi with it, and Kairi has a double take before sprinting out of the ring. She did not want to get hit in the head with that chair. Becky gives her a soft one to the back and she rolls out
Asuka puts Charlotte through the table on the outside, the one risky bump she took herself and it probably had the same or worse impact than the one Kairi took from her. Then Becky falls from the ladder as Asuka pulls the rope... Becky comes nowhere close to taking that bump with her head, instead landing her arm across the rope. It doesnt look very good. And then Asuka wins
All in all, something clearly happened to Kairi. Not 100% a concussion, but maybe 50/50 and if not at the very least she was shaken up, physically done and could barely do basic things for the rest of the match. While mostly Charlotte, but also Becky's boot still hit her in the face several times and Charlotte powerbombed her through a table.
When I heard about this match I expected to see her in a complete mess like when Paige took the kick from Sasha from behind and re-injured her neck. That wasnt the case, she was obviously hurt and shaken up and shouldnt have continued or her opponents should have left her laying because she was clearly done. But they had her carry on doing most of what she was supposed to do in the rest of the match and obviously, it was poorly done.
Hopefully theres nothing longterm wrong with her, but again Kairi has had at least 1 concussion before in Stardom. I also believe her contract is up in the new year so this could conceivably be her last match with WWE unless she signs a new deal. Of course WWE is known for adding time to contracts of people who get injured, so maybe if shes unavailable for a while they'll freeze it and get 1 or 2 more matches from her.
Heres a gif of Io Shirai giving Kairi a concussion in Stardom from a Piledriver off the apron to the floor