I would guess so, I thought TPE extensions were happening from Newcastle to Edinburgh in the near future?
They are going to be running that way shortly during WCML engineering works. I think there might be another thread mentioning it.
Yeah ive seen them working Edinburgh - Manchester via the ECML during recent WCML closures, I have just never seen them working these ecs moves.
It's running again today formed of 185126. Looks like a route learning special.