exactly. he doesnt deserve that.
his character arc is surrounding a "grand death". what he should recieve is a pathetic death. the statement that he told kinemon before skewering him ~ "face your death like a warrior! the problem with defeat is that so few people can accept it when it arrives" ~ this alone makes me think that he's gonna die while bawling his eyes out and crying about his legacy being tarnished by his pathetic death. that people wont remember him like they remember roger and whitebeard after their grand/epic deaths.
There are several possibilities, not denying that, depends on whether Oda goes down the fraud path, which could happen, no argument, and Kaidou could turn out to be a more powerful Moria pretty much.
It´s also interesting to point out that boiling a prisoner was actually pretty common (Oden) but it was only reserved for the biggest criminals. So Oda could say Wa No/Strawhats is giving Kaidou the death he did not even grant Oden (though Orochi also had his hands there), or you could say karma, he killed off Oden like that, he does not deserve to fall like a warrior either.
It´s something Oda has to decide in-between, fraud or not.