I tend to notice stories slowly changing after going on a site like newspapers.com and work chronologically to see how they shift a story where they were the main character.
Jagger and Ronnie Wood insist that “Miss You” wasn’t conceived as a disco song, while Richards said, “‘Miss You’ was a damn good disco record; it was calculated to be one.” In any case, what was going on in discotheques did make it to the recording. Charlie Watts said, “A lot of those songs like ‘Miss You’ on ‘Some Girls’ … were heavily influenced by going to the discos. You can hear it in a lot of those four-to-the-floor and the Philadelphia-style drumming.”
The second paragraph is taken word for word from the Wiki article on “Miss You” without credit. There is nothing in the article to suggest that the comments were made over time and no footnotes to that section. So we have no context in which to place any of the quotes.
How about going back to newspapers.com and citing the actual articles in chronological order?
The statements in the OP are not necessarily contradictory. Saying something was “calculated” to be a disco song does not mean it was written from the get-go to be one.
David Bowie reminisced (or not) that there are several records he had no recollection of making, due to rampant drug use. And he’s far, far from the only one, even high up the popular music food chain.