they def are fans of bts if not friends
the thing i know for sure is that they streamed the mv!! look at this
External Content twitter.comContent embedded from external sources will not be displayed without your consent.Through the activation of external content, you agree that personal data may be transferred to third party platforms. We have provided more information on this in our privacy policy.
They have always been fans and that was something they never hid. You could see them singing along and doing BTS steps during the last offline award shows held in 2020. I am sure they must be friends too seeing how BTS was initially only close to JYP groups.