I will repeat, the point of my argument why people keep making this assumption, is that GWR from what I can see, operate a fair few branch lines that would be ideal to run these trains on.
In regards to the turbos, operating a microfleet of perfectly serviceable 90mph surburban DMUs on purely branch lines is nonsensical, when you can use something a little more specialised.
Furthermore is it written in any franchise arrangements that these DMUs will be taken on by any franchise? From what I can see, saying that these units won't go to certain operators is silly, as it's all mostly hypothetical as to who will and won't receive them. It hasn't been written currently into any franchise agreements, who will receive them, that's if the units ever get past the experimental stage.