WRONG!
This is far worse than save-scumming. This is interference and meddling with combat. It's tinkering with actual chances to hit to "even out" combat so everyone has the same chance to hit or miss. It makes those garbage "73%" chance numbers lies because it's really "YES"/"NO". The numbers are supposed to be there to help you assess your chances, but they don't do that anymore.
Imagine a soccer(football) player doing a kick from the corner near the opposing team's goal. Let's say that the player has a 10% chance to score a goal. Under the rules of DOS 2, if his seed says "you score", then that player will score no matter where he kicks the ball. Kick it at the side, kick it down the field, kick it into the stands, anywhere, it'll bounce into the net.
If Larian REALLY wants to remove combat save-scumming, then they should do it by forbidding saving if a party member is in combat. This chance-to-hit meddiung method is bad.
AND Who gives a fuck if someone else save-scums? Give me save-scumming a million billion times before you give me random seed combat once. THIS IS SHIT. And I am someone who NEVER save-scums in combat, I play all fights start-to-finish unless I'm specifically testing something.