I asked the person twice where was her source and she ignored me while she responded to every other questions. It's impossible that she did not see both my questions.
Moreover, how is it possible that someone from a foreign country can promote in Korea this year?
I tried searching if there was any news/announcement of the group debuting in Korea and found nothing. I even scan through the Twitter time line of the group's music label back to Jan 1 and found nothing about Korean activity.
I also don't think they're going to debut in Korea... Tbh, OP has been making threads with content from this obscure Dotasiaent yt channel for a while, I wonder what's going on...