You're almost entirely wrong there Andy.
What you described is pretty much the case with every other now-deleted former GB SOTA summit, but not the case with G/LD-002 Scafell.
This was always known not to be P150, but was included, subjectively, as a one-off, by Alan Dawson in the original book "The Relative Hills of Britain". The justification given was that the saddle route between the two was only for highly skilled mountaineers, and for the vast majority of hillwalkers, the drop between would easily exceed 150m.
I think he realised eventually that such subjectivity could be applied to thousands of situations in the UK alone - and sensibly decided to amend the criteria to 100% objective - either it's P150, or it isn't.
Now whether this happened a few days after the start of SOTA, or whether the then MT / G AM discovered this deletion a few days after the start of SOTA, I am unsure.