It's like a physical DVD set typically containing deleted scenes/director's cuts, NGs , commentary from the cast…
Thank you very much for this detailed answer. After all, I am very sorry that they are not made them public in the same way as the original parts. It means I'll never see :(
Can someone explain what this BluRay thing is? I heard the cut scenes will be made into a "special edition." Where can I watch this outside of BluRay? Where can I get it? I don't know BluRay, they won't share it somewhere else freely?
In principle, a lot of scenes were not broadcast (for example Hwang Gi Nam and Myung Hee's father story in the past) because they no longer fit into the time frame.
Filming will begin after the casting process has been completed. The production is slated to start during the second half of the year. The drama will reportedly air in the first half of 2022 and is in discussion to air on tvN.
In principle, a lot of scenes were not broadcast (for example Hwang Gi Nam and Myung Hee's father story in the past) because they no longer fit into the time frame.
(Source: https://www.google.com/amp/s/www.kdramapal.com/vincenzos-yang-kyung-won-kwak-dong-yeon-courted-big-mouth/amp/)
"According to a media report delivered by Ilgan Sports on July 23, the cast lineup for tvN's legal drama "Big Mouth" has finally been confirmed."
(Source: https://www.kdramastars.com/articles/121294/20210723/its-okay-not-okay-kwak-dong-yeon-kim-joo-hun-reunite-tvn-big-mouth.htm)
Update: I heard the filming will start in August. So I think the airdate most likely expected around in October.