It will interesting when we get more details about the new rolling stock. To be compatible with the majority of existing stock it would have to come from Siemens, unless some other manufacturer can do a deal with Siemens to get the necessary information. If its not compatible with 444s and 450s First /MTR will still have three different systems: the new stock, 444/450, and the re-tractioned 442s (unless they are made compatible with one of the first two).
If I was running a ROSCO, I think Id be feeling a little nervous about buying 750 new carriages for a franchise thats only seven years long (with a possible short extension), bearing in mind what appears to be going to happen to the 707s. Id hope that the new trains for this franchise could also be used on Crossrail 2, but Crossrail 1s trains have three doors per carriage. Should I insist that the new trains for First/MTR should have three doors? If not, I could be looking for a new home for several hundred carriages in less than eight years time.
The franchise award raises the question whether theres any advantage in being the incumbent operator when bidding. On the face of it, there should be: the incumbent knows many things that nobody else does. On the other hand, perhaps being the incumbent limits your vision. For example, First/MTR are proposing four trains per hour to Portsmouth. Someone in an earlier post said that had been tried under Stagecoach and it hadnt worked. I wonder if the Stagecoach bidding team considered 4 tph to Portsmouth and decided, from experience, that it wouldnt work. An outside bidder may be more likely to say Lets look into that. Well discover later whether it actually will work, having been told repeatedly that theres no room on the main line for any extra services. Combining it with reduced journey times may be brave as they say.