There is provision to unilaterally change treaties if ‘unforeseen events occur’, for example the pandemic and suspension of freedom of movement, or Force majeure.
However, the NI protocols were specifically designed to take into account the possibility of no deal and in that event protect, the peace process and avoid a hard land border in Ireland. In short, events that were entirely foreseen and catered for.
To try and unilaterally change the NI protocols when, to use the same language as the NI Secretary, ‘circumstances have not changed’ will not be accepted by Dublin principally and the EU in general.
Usually when a criminal admits to a crime you tend to be sceptical of his justification for doing so.