@GolD.:
I doubt that VegaPunk is a revolutionary or isn't actually 100% with the WG. _Thou I do think that Vegapunk isn't pleased to be forced to make weapons for the WG, and might rather be making technology that could actually help better the world.
And I don't think they would just remove him from their power without reason. I feel the WG would only give his spot as a ShiChibukai to another pirate if they had another pirate in mind already, if the pirate accepted, and to only increase their military might.
=DVegapunk is not a Revolutionary.
However, Vegapunk working willingly for the WG is unconfirmed. He did do incriminating acts, such as Accepting Kuma's offer to program him to guard the Strawhats ship… which is quite suspicious. His actions don't seem like his working for them 100%. So I do believe the WG might have their reasons in not trusting Kuma or VP even if they work for them._