We then have to take "Enterprise" and all of the prequel shows as part of an alternate reality. Then again, the way Star Trek has so much time travel, and plays fast and loose with how time travel works, we could have had countless divergent realities. Apparently, the Kelvin timeline did not prevent the original reality from still existing since "Picard" is supposed to be in the original reality. Or, maybe, it is an alternate reality and that explains the glaring contradictions.
At any rate, once you have time travel in the mix, judging whether something is original or altered is impossible and moot. So, yes, Star Trek was altered from a 1960s concept of what the future will be to a 2020s concept, neither being remotely what the future will really be.