This video sums a lot of stuff up fairly well.
Roddenberry himself was adamant that Star Trek’s history had to remain a possible history for viewers. So, the dates can slip as long as the major events don’t.
I’ve seen this rationale attributed to Kurtzman and Goldsman, as the excuse for changing events in lore in Strange New Worlds compared to the rest of establish Trek, but never Gene Roddenberry.
During The Original Series, a lot of things were still up in the air or being worked out. Once The Next Generation started, Gene finally locked down a lot of lore and the general timeline of events and it hadn’t changed, even as notable dates came and went… until Kurtzman took over Star Trek.
All of the new Trek shows are clearly part of a new Prime timeline, which is fine because they change whatever they like. In the original timeline the Eugenics Wars occur in the 1990s, the Millennium Gate broke ground in 2001, the Bell Riots occur in 2024, WWIII occurs in the 2040s/50s and First Contact occurs on April 5th, 2063.
I’m not attributing anything here. You’re arguably the one clinging to your head canon.
I’m an older person who was around to hear other OG fans complain about this ‘alternate universe/timeline for TNG’ theory in the late 1980s. And to see how the Great Bird himself responded.
Roddenberry went on the record saying that the timeline had to adjust to always keep the show’s future as a possible future for the audience. He defended the shift in the timing of WW3.
Goldsman, who has been a fan longer than almost any of his detractors, would have heard this more than I did. Goldsman organized one of the very first clubs and fanzines as a preteen, and attended the first ever convention in New York City.