It was mentioned to me by a colleague (and by fleet control at EMR), and in my original post I did make it clear that I
wasn’t sure on the truth of it. EMR are stretched with rolling stock as it is, what with 153s leaving the fleet and the 170s taking a long time to filter through from the West Midlands so it could well make sense. The original plan was for the 156/9s to be the first to go and it was said by the above that 156401/415 would come back in exchange for two 156/9s. It must be said that plans can be turbulent and things change
If you are doubtful, the best thing to do is to
wait and see.