GNER?
National Express began but did not finish a complete rebrand of all of the old GNER stock, but they certainly focused on entirely destroying the old GNER brand, which found it's routes in the original rail companies that built the lines the east coast runs on (GNR & GER), and replacing it with their bland corporate National Express image.
As a monthly user of the North East Coast line for the last decade, the service distinctly degraded under National Express from the previous GNER service and has not subsequently improved under the new government owed line. I agree that it should be a condition to return the stock stripped of all branding.
It seems to me that too much of the focus of National Express was on it's image and branding or rather style over subtance. I hope that's not the same for the new company.