I was under the impression that "Wales and Borders" had been stipulated as the franchise name. I stand corrected.
I think that "Transport for Wales" has its benefits. There's something very corporate about it, in a good way. The image and branding is, as the saying goes ,"on point", and I think the distinctive look will make passengers very much aware of the change that has been made and the promise of improvements in the future. It's certainly a clean break to go from "Arriva Trains Wales" to "Trafnidiaeth Cymru", and even the least 'industry-aware' passenger will notice that change.
There are certainly arguments from the other side, though. It might seem very out of place in, say, Crewe, to find "Transport for Wales" taking you to Manchester Airport, or in Bidston rattling through central Wirral towns.
If the Welsh Government have been so eager to stamp this identity on the new franchise from the start, including the font and colour scheme, they have to take ownership of the good and bad. There may well be times when TrC/TfW slip up, suffer timetable problems, fall short of expectations. The blame will go to the name on the side of the train, from most passengers and in most media outlets. That means Keolis/Amey are somewhat shielded from immediate criticism. How long the Welsh Government will allow this to happen is the next big question.