The ground handling at LGW is outside the franchise agreement (SunAir / ComAir don't use BA either) and GB is quite right in the current tough trading conditions to seek out the cheapest options for front of house / ramp services and engineering cover.
Indeed its already Aviance who provide many of the ramp services at LGW. They have been invited to tender again as have BA. Simple economics i guess.
This is only for LGW, not for LHR.
I'm not aware of what WW's master plan that you refer to is? Do you mean getting rid of all the regions (Flybe) and now LGW therefore retrenching to LHR?
Anyway, the tender process concludes in Nov and the new contract starts Apr 1st.