Well if you read that IN A YOUTUBE COMMENT it has to be true right? :)
Seriously though, I don't see how it would help or hinder anyone. The DB is an assassination service, which means anyone can either used them, or be targetting by them. So removing them of the equation just makes it much harder for anyone to put a hit on someone else, or to be the target of such hit. I don't see how it would benefit the Thalmor more than anyone else.