The big temporal shift took place when TNG’s premiere ‘Encounter at Farpoint’ was written to place WW3 and first contact into the mid-late 21st century.

TOS was very specific in saying that the Eugenics War was a precursor to WW3.

Roddenberry wanted to ensure that the franchise’s optimistic future was always a future possibility for viewers. So he insisted that TNG reset the date of WW3.

At the time TNG appeared, there were die-hard gatekeeping TOS fans that argued that this time shift broke canon and meant TNG was in a different universe despite McCoy’s appearance in the premiere.

SNW just confirms the physics of temporal slippage in the Prime timeline as the consequence of all the various intertemporal incursions over the history of the franchise.