Patch Notes Up!

[LunaFaye]

it says "party ko", which means when your whole group died and all were dead at the same time

single player ko's dont matter

Unless you logged out or got dc'd and then kicked from the party. It will show a KO:1 in that blue screen and that means you're disqualified and have to start over lol, but than again it will only affect the player that got kicked/dc'd/intentionally logged out....

[HyoMinPark]

Unless you logged out or got dc'd and then kicked from the party. It will show a KO:1 in that blue screen and that means you're disqualified and have to start over lol, but than again it will only affect the player that got kicked/dc'd/intentionally logged out....

It's still a party KO that counts as disqualification, not individual KOs. Since you have to enter 101-200 in a fixed party that has been established since either floor 1 or floor 51, the screen will only show KOs for that party, not for just you as it would if you were doing matched.

If you DC, and your party remains in the current tier of floors, you can still reconnect back into those floors just like you can in every other instance. It wouldn't be ideal for your matched party to kick you if you DC'd in there, since it would also disqualify them from entering 101+ as well (since 101-200 have to be an established matched party--kick one member = instant disqualification for the rest).

[EusisLandale]

Unless you logged out or got dc'd and then kicked from the party. It will show a KO:1 in that blue screen and that means you're disqualified and have to start over lol, but than again it will only affect the player that got kicked/dc'd/intentionally logged out....

That would still disqualify the whole group if a single person disconnecting gives only that person a party KO count. The others would not be able to continue on as one part of the group, that must stay as is, is not permitted to keep going.
I doubt that just disconnecting will mark your save as a failure, a full group DC or singular with everyone else actually dead sure, but a single person means that the party is still in there and the dungeon is still active.