"Can a pop song become traditional?"

I'm still inclined to answer yes....

here

and before that,...

here... https://www.youtube.com/watch?v=77lc1yxBtFE

which was happening at the same time and place as this.. https://www.youtube.com/watch?v=89C_PQ_kuUk.

Then just follow the folk process trail back another 5 decades to the song's pop / rock origins....