Some Korean team members already have begun to share news of the re-assignments, others will find out in the coming days.
Meanwhile expect some change both at senior leadership and across the teams. Those receiving promotions should be congratulated--promotions bring considerable status along with a boost in wages.
On a more personal level...
As the holidays approach, you may wish to greet Korean colleagues with:
Sae hae bok man i ba deu say yo! (Seasons Greetings)
Hint: Break the greeting into: sae hae bok—mahne—bah deu say yo
Sae hae bok man i ba deu say yo! works well both in person, in a card, or an email. It is a common seasonal greeting actually good into the New Year.
If you have a specific questions, feel free to contact firstname.lastname@example.org