No: the word “pop” was originally just a shortened version of “popular” and there's always been popular music.
I think the term “pop” started to be used in the 1960s (at least in the UK) when the charts were taken over by (mainly) groups playing modern music as opposed to the stuff in the charts pre-Beatles that appealed mainly to parents rather than their children.
Pop music was never a “type” of music - basically it just meant music that sold well and entered the singles chart. In the UK we had Top of the Pops - a TV programme that focussed on the fop 30. Over the years it featured Pink Floyd, Jethro Tull, ELP, Family, Steeleye Span, The Dubliners, Fairport Convention, Black Sabbath, Deep Purple, Curved Air, East of Eden, Gary Moore, Eric Clapton and lots of other “serious” artists. This though, together with The Osmands, Brotherhood of Man, The Archies, Rolf Harris, The Nolans, The Sweet, Clive Dunn, and lots of other “less respected” artists was all “pop music” - at least so far as my parent's generation was concerned.