If it's well timed it could well provide feed onto the BA longhaul network at gatwick and if operated into ORY could even supply feed for the openskies routes
The BA long haul operation feeds holiday makers to former British possesions in the Carribbean and Florida. The French tend to migrate to former French colonies. Also BA need to maintain some point to point on LHR-CDG as well as the long haul feed so having a LGW operation would dilute further that already contracted market.
if operated into ORY could even supply feed for the openskies routes
I think BA would prefer to feed BA at LHR than a subsidiary in France, aside from the fact you'd be way quicker from London direct.