The couplings look very similar to that of the BR class 20. That's what I think its gonna be. For Tees Valley most likely.
I think you're right about the train, but the buffer beam (I think that's what they're called) is red, and the BR Blue livery has a blue one. It could be in Railfreight livery but I think it might be a green one for the WSR.
Good point, it definitely wont be for WSR though it will most likely be for Tees Valley or NTP. Lets be honest people will be a but disappointed if WSR gets another diesel. Especially as everyone wants a steam loco.
Looking through the text, it doesn't look like anything specific, more of a potential logo? The colours... the blue and yellow stripes and the red and grey stripes. 2 separate designs judging by how one is under the 9th June and the other just under the 2020....