I thought the whole point about the changes was that it affected such a vast number of other routes/TOCs/services etc. Why should all that be undone so (relatively) soon ?. Are you suggesting that those looking into the current issues will be unable to solve it ?
As a whole, yes it does affect other areas. However on the GN side at least, VTEC is the main other user, and their timetable has only barely changed - mainly tweaks to minutes here and there to fit round GTR. This is the only other GN user south of Peterborough and Cambridge apart from a small handful of GC and HT services. So you’re then left with a half-hourly Cambridge to Liverpool Street service, a handful of hourly or less regional services at Cambridge and Peterborough, plus of course GA peak King’s Lynn services -- all of which are comparatively insignificant compared to the busy GTR services.
South of the river it would be much more of an issue, likewise on the Midland side. Hence it's probably best to leave these alone, and somehow find a solution to what to do with the 2tph Horsham service and 1tph Brighton service, many or most of which aren't running now anyway, but at least most of these destinations have alternatives, or could have an alternative provided relatively easily.
I can’t see the current service being able to be fixed as it is, it’s just too much in meltdown. Currently sitting on a train into London, about 15 drivers all travelling pass, no idea what they’re going to be doing, can’t get through to anyone to make arrangements about their duty, many of whom should have already picked up a train, and several saying they refuse to pick up if they aren’t guaranteed transport home. The impression, in full view of passengers (*), is one of total and utter chaos, an operation which has lost control of its resources.
I think many observers on here who haven’t had first-hand experience of the service have little idea just how far this railway has melted down.
(* As an aside, it really looks bad to have large numbers of drivers travelling around on the cushions, openly and loudly slagging off their employer, whilst farepaying passengers are standing, but that’s another issue)