Whitebeard had his ‘treasure’ to protect. His territory, his family, his hometown. He had a tough choice to make.
He knows Wano is hard to get to, hard to attack, and easy to defend. His ship was severely damaged getting there the first time.
Where at Marineford, Ace was still alive and Whitebeard was dying, and he had a chance to save Ace. With Oden he would have only found out after it was over, and would not know all the details. He might not even know exactly who to take revenge on, only figuring out later that Kaido is a big part of it. Maybe Inu/Neko could fill him in on some details, if they were in contact.
But given the situation, and his history, I think he would choose protecting his family and his treasure, over revenge. If his family was in danger, he would try to protect them. But if they are already dead, all that is left is revenge, and a revenge could cost you most of your territory and much of your family if others attack (e.g. Big Mom could attack his territory while his forces were attacking Wano).
I think that is part of the Four Emperors balance — no single one can make a big move without the others opportunistically moving in. When two seem to form an alliance the World Government worries, when they are all on their own they have huge territory but negate each other.
Whitebeard packing up and taking his fleet to Wano is not some trivial thing to do. Luffy and Law can do it because they don’t have territory to defend. The minks are obligated. It’s more like a secret ops plan than a flat-out war (so far). Whitebeard would have had no insiders, no spies, at best Izo’s knowledge. I’m not sure that is a recipe for successfully getting revenge on Kaido/Orochi without massive casualties and losses. And then at the end, is a Kozuki put back on the throne?
I DO suspect that if Whitebeard was alive, and Kinemon/ Inuarashi/ Nekomamushi/ Luffy/ Momonosuke came to him with the current situation he would help out. But the situation 20 years ago after everyone vanished was different.
