You have carefully selected from Neilsons opinion (that's what it is

Yes.
He is a historian.
There is dispute, as I said.

Definition of revisionism, Kinealy,
"In Ireland, however, the dominant approach continued to be based on revising and destroying the traditional nationalist view of history. This approach became known as 'revisionism'."

" A key objective of Irish revisionism was to exorcise the ghost of nationalism from historical discourse and to replace it with historical narratives that persistently played down the separateness and the trauma, and derided the heroes and villains of Irish history."