Nah, Zoro still hasn't yet completed his role in the Kaido fight. He still needs to:
- Give Kaido a new scar or reopen Oden's own scar
- Be recognised as the "monster samurai" of the likes of Kozuki Oden
- Blacken Enma
- Kill Kaido
Zoro used barrier COA to block Hakai. That's what you see here:
Nah, I don't think they'll betray each other:
- Mama sees Kaido as her little brother
- Mama has tried to save Kaido many times during this battle
- While Kaido was dazed from Indra, she struck him down with Indra before he could go for the kill.
- She warned Kaido not to try and tank Hiryuu Kaen
- She followed up by sniping Zoro again with Indra afterwards
- She chastised Kaido for underestimating Zoro
- She's shown concern and worry for Kaido
- She inquired on his condition after Luffy knocked him down with Kong Gatling
- They have friendly banter
- Kaido asked Mama if she was still in shape enough to perform Hakai.
It will be incredibly shitty of Kaido to try and betray Mama after all the assistance she's provided him, the genuine worry she's shown for him, and just how straightforward she's been in her dealings with him. If Kaido doesn't assist Mama, it's because he
can't.