Just to be nitpicky Air France and KLM are Skyteam not Star

But the antitrust concerns don't have anything to do with the total number of carriers that fly over the pond, but due to BA and AA's stranglehold over LHR slots for flights US-LHR.

With the new open skies agreement taking effect next summer maybe the regulators will be willing to reevaluate their stance if AA or BA applies to be allowed to do codeshares/give/redeem miles on their US-LHR flights.