I've been a Trek fan since the age of 3. I'm 28 now. I thought I knew almost everything, but this is seriously the first time that I've heard the postulation that STII "overwrites" STI. I really never knew some looked at it that way.
I'm paraphrasing, but ISTR somebody who was on the production saying they asked Nick Meyer at the time how they were going to explain the uniforms being different. Meyer's response was, allegedly, "We don't. The first movie doesn't exist."
(I don't think there was ever anything malicious
in that statement, nor that anybody involved was seriously
trying to "overwrite" the first movie, despite the fact that TWOK obviously originally went out without a "II" in the title. But I do think it's an indication that to those who mattered, ie. the directors and producers, TMP was irrelevant. Certainly despite it's box office success the executive level at Paramount seemed to look at TMP as being an embarrassment.)