Fellas you got to consider motive as well, always the number one reason behind one's devious misdeeds
If any of the Vegapunks were really working with the WG then they're making a high risk low reward gamble
All of them are more than well aware of how the WG is, not to mention that they are parts of the main Vegapunks who hates the WG and might as well of been a revolutionary if that scene from Ohara is anything to go by.
So if they say yes to getting the rest of the punks killed then what do they gain when the WG does what it does best and ties up a loose end
a 3rd party, especially someone like Blackbeard, would benefit the most from kidnapping the main Vegapunk and gaining control of the Seraphim. Blackbeard is also someone who was used to help introduce the Seraphim and got a taste of their power first hand
Add in clues like someone being in a room but the sensors not detecting anything and how a VP level authority made an order out of nowhere and we got ourself a heist from ol' Blackbeard himself.
And who better to knock out communications than Caribou who did something very similar in his time during Udon, and has a lot of info to give to a certain special person. One that would use said info to their greatest advantage.