Maybe Chris Grayling's vanity has been sated by picking the names for all of the franchises the DfT has let recently. The
Agency Agreement 3 does include the following paragraph:
7. Welsh Ministers shall ensure that the Brand Guidelines developed with and issued to the Franchisee on trains, stations and for marketing material and publicity (excluding that for Wales-only services), shall recognise and demonstrate the cross-border nature of the Franchise and continue to comply with any licensing requirements regarding the use of trademarks licensed by the Secretary of State to Welsh Ministers.
It could be there to ensure any network maps show the border, for all I know.