No it goes back far further. For example Southern 3 years before the next franchise was due to start going to see DfT to tell them they need to fund massive driver recruitment and programme on the existing FCC and Southern franchises including increasing the scale of the driver training set up to cope with the scale of the task needed (the bottleneck 377/5 has pointed out especially with all the new stock and cascades). Govia there for have very good evidence that DfT goofed up very early on and DfT probably don't want this to surface. This isn't the only example either.
The driver numbers on FCC dropped faster after bid submission date than before which would have left all the bidders with a bigger issue to solve on driver training than DfT anticipated.
If that's true, I apologise to GTR. Indeed, I have always said that most of the problems are of the DfT's doing (like making GTR do its dirty work). The problem is that once Govia realised it wasn't going to make any money, it had no incentive to do much thereafter.
So, the DfT gets most of the blame - yet GTR doesn't get off scot-free by a long shot.