The Brief: The term "comeback" is used by K-pop stans in reference to the release of a new single or album.

DEEP DIVE
A “comeback” is a term used among K-pop stans to signify the release of a new single or album. The term is in reference to the K-pop group or member returning after a break or hiatus.
“Comeback” used in this manner is different than the term used in reference to a clapback or insult.
https://twitter.com/vantefIwr/status/1291404190758182915?s=20
#kpopstansareoverparty
anyways blinks and armies, get ready for their comebacks. the power we hold. i swear the locals aren't even ready. pic.twitter.com/vy2nrfHz8I— chloe lui (@chIoeIui) August 6, 2020