Speaking about Kuma, the former revolutionary... why do you think he volunteered himself to be weaponized by Vegapunk? Why's he cooperating with the World Government when we know the revolutionaries sits at a complete opposite side?
Probably to gain top secret intel from them about either the WG's nefarious actions or Vegapunk's technology. As a cyborg, he'd probably have sufficient data on the government's activities and probably didn't mind being sacrificed as someone the Revolutionaries could pry information for if they had the resolve to capture or even kill him.
Shame that the perfect opportunity to have this revealed instead of being perpetual mystery bait was skipped over in favour of showing the highly important plot line of Luffy making dumb decisions on Wano.