It is very unusual for a super hit group to go on almost a year of hiatus in their rookie era.
According to some rumours it is due to bang/hybe meddling in mhj/ador's plans, leading to postponement of newjeans comeback schedule by 2-3 months to make empty field for illit's debut so that illit (fake newjeans) doesn't gets destroyed by newjeans (the real one). This theory does makes sense.
Im curious about other plausible reasoning