I think this is a very clever piece of strategic decision making at bmi. They’ve been talking for a while now about increasing their medium haul market, and this way they can jump straight in, with fleet commonality, and without having to sacrifice any slots at LHR to achieve their goals. The BMed markets are very high yielding (as are may medium haul points from Europe) so should provide a good rate of return.
I’m not sure how BA will cope, they did very well on premium traffic connecting from these routes across the atlantic. So it wouldn’t surpise me if bmi suddenly had some competition from BA on some routes, which would be likely to skim the cream from the milk and maybe have a negative effect on bmi’s purchase. All to wait and see I guess.