1. What does it mean?
In music and entertainment coverage, 역주행 describes a previously released work finding a new audience or returning to popularity. A shared performance clip or renewed discussion may help people discover it later.
Also written or said as 역주행하다, 음원 역주행, yeokjuhaeng
2. The nuance
It is not simply another word for a newly released song doing well. Elsewhere the word can mean traveling the wrong way or going through a sequence backward, so check whether the topic is charts, viewing order, or traffic.
3. Examples
“몇 년 전 노래가 짧은 영상으로 알려지면서 역주행했어.”
A song from several years ago climbed the charts after people discovered it through short videos.
“역주행 소식을 듣고 예전 앨범의 다른 곡들도 찾아봤어.”
After hearing about the song's resurgence, I looked up the other tracks on the old album too.
Sources
Nate News: Korean usage in the press
References support the meaning and usage. Example sentences are written for NoCapWiki.