Kuma strangely seemed to be cool with it. Honestly, though, the whole thing with Kuma was strange, and it was never really clear why he even allowed the WG to cyborgify him in the first place, considering he was a pirate and rebel spy. I'm sure the WG has also made Vegapunk do plenty of things he didn't necessarily want to do. Most intelligent people seem to notice that the WG isn't all sunshine and rainbows.