In Western terms it's way easier: a band is active until they officially disband. It doesn't matter when there will be new songs. But I doubt this works for K-Pop, otherwise every K-Pop group on hiatus could be on Moguri's 'active' list.
I would say that every K-Pop group is active that releases new songs during a year or tours during a year (including show performances). For example, Everglow. They already toured again before their official comeback. But that's probably a wrong definition of 'being active' in K-Pop too.
but obviously we are referring to kpop and not western music so we should adopt a kpop definition no?
also I can accept active doesn't mean comeback within the last 12 months as long as the group as a whole does something - I would accept that touring implies still active
individual personal activities of the members of the group - I would not count as consisting activities of the group (like for example BP but then again BP members did partake in their 8th anniversary which I would count as a group activity)
thus for GG since I am less aware of BG
the groups mentioned that I would count as active from moguri's list would be
BP
Dreamcatcher
Oh My Girl
RV
Twice
I'm not sure but what group activities have WJSN taken within the last year?