Delta told me several confusing things about trying to get a seat assignment. One was, with my Diamond status, that I can get a seat assignment in advance. However they were not able to select a seat and even after contacting Korean they say I do not have the right fare class.

So I have to wait until 24 hours before and most likely end up with a middle seat in back as a Diamond?

I think I will switch this leg to Singapore airlines, lose the miles, but gain a seat assignment!