Possibly true.
That song, like many of the period, had the "psychadelic awakening" vibe, so they certainly fall into a pretty specific slot, no different than say...Doo-wop music.
Though I think "Tomorrow Never Knows" might be cool today, as there is a lot of retro appeal. Maybe done without as much "trippy" flavor, and with more of a Rock edge....the song's message could fit into a lot of time periods.