Just earlier on this year, BA and Iberia left the AEA (Association of European Airlines) in protest at the anti Gulf airline stance that was being promoted within the association. Willie Walsh said on record that 'global liberalisation of our industry is fundamental to our future growth and we are not willing to compromise on it'. Those are very different words to a few years back when Willie Walsh was highlighting the threat that Gulf airlines posed.
He knows that the threat of fifth freedom routes to/from London operated by any of the ME3 is almost non existent. Heathrow and Gatwick are slot constrained and any slots that were available, would be best spent on increasing the frequency from London to their respective home hubs.
The gap in the jigsaw puzzle here is within the regions. It's true that the US carriers would suffer should any of the ME3 start transatlantic services from the UK regions but it has the potential to be good for the consumer. Lower fares and still a wide degree of connectivity being available. If you were to fly on Delta (for example) then you would probably be connecting on a Delta flight when you arrive in the US. The ME3 have the benefit of providing interline options that could involve a number of US operators. This might change depending on what Congress has to say with the discussions that take place in the near future. Whilst EK has a codeshare agreement with JetBlue, they also have interline ticketing agreements with a number of US operators and even with their arch rival Delta.
It may seem that I am a stanch supporter of the ME3 but I am not. I felt it was perhaps useful to highlight just how little resistance you are likely to find within the UK to fifth freedom routes across the Atlantic that would be operated by any of the ME3 airlines. Also it is nothing more than a myth that the ME3 would provide little or no connectivity as well within the US.