The WYD Seoul 2027 Preparatory Committee provides the official position of the Catholic Church in Korea regarding "Julia Youn of Naju":

Unapproved by the Church: The Archdiocese of Gwangju and the Holy See (Dicastery for the Doctrine of the Faith) have declared that these activities have nothing to do with sound Christian spirituality.

Exercise Caution: Do not mistake unofficial social media content or publications for Church-endorsed information.

Canonical Consequences: By formal decree, attending or celebrating sacraments or liturgies at the Naju site results in latae sententiae (automatic) excommunication under Canon Law for all Catholic faithful.

Pilgrims are strongly advised to seek guidance only through the official channels of the Catholic Bishops’ Conference of Korea (CBCK), local dioceses, or the Holy See.

[Catholic Bishops’ Conference of Korea — link]

https://www.cbck.or.kr/en/News/20261270?search=naju&gb=subject

https://www.cbck.or.kr/en/News?gb=subject&search=naju

[Archdiocese of Gwangju — link]

https://www.gjcatholic.or.kr/file/partoral/4121?share=&cat1=106&page=2

https://www.gjcatholic.or.kr/file/partoral/4119?share=&cat1=106