The only flow where a change is now required is Huddersfield to Edinburgh. Or the even smaller flows from Leeds to Morpeth, Huddersfield to Berwick etc.
That's true. However, Northern has an almost clockface hourly service between Morpeth and Newcastle, and the new Newcastle-Edinburgh service provides greater local connectivity.
Unfortunately it's difficult to justify running trains purely on the basis of one small flow.
...then Morpeth would suffer an even worse service than it currently gets?
Having a standalone service means much better reliability than a 5 hour long through service.
It was initially temporary because of Covid. There was the opportunity to bring it back in May, but that's not happening because things have ... changed.
Yes, pretty much, but no-one in the government is really being straight that this is what is happening.