Okay here is what I think is going on:
Michael Vaughn wanted to tell Syd about what he is doing and everything and Prophet 5 found out (by the way I suspect that Vaughn is either involved with Prophet 5 or has some VERY VERY detailed information that they need to get from him) buy anyway...
The show already had Sark/Lauren as a combo..remember when they were pretty much groping each other every episode after they attacked someone? She is SO over..Sark on the other hand is more than welcome to come back!