Can kpop artists release music during enlistment.

I remember vaguely there was a member called out for trying to release or actually releasing a song surfing enlistment (I think it was a bigbang member but that's not the point) why armys around me think hybe will bts' stuff during enlistment? Is this even possible?

If it was previously recorded before they enlisted, yes. They are only supposed to do public/volunteer work while enlisted, but anything they did before that is fair.

Several have had songs come out after they enlisted. Baekhyun and Chanyeol were both on EXO's last album, Baekhyun had several OSTs last year, Hui from Pentagon featured on their album after he enlisted, Zico was on Epik High's album last year, Shownu was part of Monsta X's English album that was released in December. Songs they write/produce for others can also be released provided the work was completed before they enlisted. BtoB also had the members who were already out release an album with songs written by the members who were still enlisted.

This is something we see more often with actors who will film a drama or series before they enlist.

No, not a Bigbang member. Bigbang barely breathed during enlistment. GD got dragged for appearing in a friends instagram photo during authorized leave, and antis were trying to call it a comeback...

Other idols have continued to maintain social media and careers. Basically it depends on how many people are waiting to jump on them at the first opportunity.

BigBang released Flower Road not long after they had enlisted and it caused a bit of a mess but because it was recorded prior to their enlistment there really wasn't anything wrong with them doing it.

Since then it's become more and more common for artists to release things during their enlistments. As long as it's recorded prior to their enlistments and they're not directly making any money from it (i.e. it comes from the company and the company hold their profits until discharge or something weird like that) then there isn't anything wrong with idols releasing stuff during their enlistments. Chanyeol releases monthly videos through Studio NNG, Shownu was a part of Monsta X's English album last year and there are other examples about. So it's entirely possible if/when BTS enlist that they will do similar things to this and record videos or something to be released during their enlistments.