Asiana bought the ticket since the schedule was changed, so they presumably did a courtesy for this as well.

BUT:

Korean Air SEEMS that they will do it from a quick Google!

https://www.koreanair.com/mobile/glo...-check-in.html

If you change to another international flight, it doesn't say what airline, it just says that they will check it through. BUT if you are flying Asiana to somewhere in Korea domestically, they will not do it.