If you have ever been to a Bryan Adams concert, he has probably explained that he wasn't waxing poetic about The Summer Of '69 as far as the year 1969 goes.
The song is purely sexual in nature as evidenced by the position mentioned in the title. With the song getting play during Summer 2020, it was time for someone else to ask Adams about the meaning again.
He recently said in an interview, "The song is a bit autobiographical, but it’s really about summer love and, in my, case being a musician. I love the song Night Moves by Bob Seger which is about getting laid in the summer, and I always wanted to write an answer to that."
Adams went on to say, "There is a huge misconception that this song is about 1969, but it’s not. The reason I chose 69 is because of the sexual position."