why is the Manchester to Edinburgh not been cut back in a similar fashion
There is a very significant difference between the MANGLA and EDI routes. Both RBS and HBOS have significantly sized offices in both MAN and EDI. The financial traffic on such routes, even though the banks are suffering just now is high. I imagine that GLA, although still a big market does not have quite such high yield traffic.
This is good news for BE though who now have the market for themselves and have managed to grow the market since the acquisition of BAConnect.