If Yamato faces a strong opponent on the way to the roof, I'll be content.
Honestly, I kinda expect her to be cheering on Luffy but also to act as quite a distraction to Kaido. Will she be helpful in that fight in a strength-sense? Maybe, she seems strong but it's Kaido. Best I see is her assisting if Luffy gets a bit overwhelmed. Zoro and Sanji already put their faith in Luffy to beat Kaido, wouldn't be surprised if Yamato does the same.