The HND-GMP reopening (originally for "early June") delay was supposedly caused by necessity to hire additional staff and set up arrival screening apparatus, and the new date is supposedly 6/15. But I suspect it will be later. Reasons:

1. JL has massively cut back its tentative June schedule. Yes, 6/1-6/14 outright canceled. Then there were initially 3x flights daily from 6/15 on (still selling as of May), but they first reduced it to Thurs and Sun only (meaning earliest possible is 6/16), and presently down to just one morning flight on those two days (all mid afternoon and evening flights canceled). That's for Japan--> Korea direction; I don't remember the other.

2. A South Korean politician is set to board the ceremonial reopening flight on 6/19, so that might be the first.