Given what Avanti said above, this does seem like a(nother) Euston gateline issue. When are that TOC (and it was the same in Virgin days, so there is clearly a cultural issue that TUPEd over) going to manage to put in place effective management processes to ensure that staff, you know, actually do the job they are being paid to do correctly?
It's like the Coach K thing all over again, but in a different context.
It does sound like it could be.
Where is the incentive? They are focussed and indeed must be trained (either from above or between them) to reject which often forces passengers to buy new tickets or excess when it is questionably necessary and of course on many occasions when it absolutely isn’t necessary. No operator is going to do anything to stop this sort of behaviour because to do so would reduce revenue. They would much sooner let 1 or 2 customers per day privately complain and pay them off and hope it doesn’t go public.
Of course, as we see here, it’s not gone to plan in this instance but as you say, just because they’ve made a statement doesn’t mean they’ll tell the gateline staff to change their response, nor does it mean the gateline staff will pay any attention even if they were notified.
Also we have to look at how long this can continue, how long are they prepared to allow this travel, just a week or for any passengers who purchased before the time table changed (which would be the correct way). And of course there are further complications to intermediate stations like Macclesfield.