This all depends on the route the OP is flying. Plane type means different seat type. If it's a 747-8 that's the best biz (suite) and F seat (huge suite) for Korean Air. Some 777 have the same new seat, but many are the old lie flat. A380 also the old lie flat but has the bar.
I haven't seen anything in Korean media about reduced service, or anything on their site, but I haven't been looking a lot actually. Not many Korean flight review. Juding by this one - even in economy - it looks like full normal cabin service!
https://cafe.naver.com/nyctourdesign/675341 He even ate food in the lounge so it looks like some type of buffet is active. Honestly, here in Korea everything is "normal" again these days it feels - just no one traveling internationally.