There are a few different meanings that are important to note at this stage of the offseason.
First, it means that in the evaluation, Roethlisberger was obviously found to not have any serious mental defect that is causing him to behave in a manner that the NFL does not find acceptable.
It also means that the many concussions that Roethlisberger has endured do not have anything to do with his behavior.
Second, it means that if Ben can stay out of any trouble between now and the start of the regular season, his suspension will be reduced to four games instead of the original six.
Third, with Roethlisberger being cleared to return to the Steelers, Mike Tomlin is going to have to decide who his starter is going to be for the first four regular season games since the Steelers are going to be without Roethlisberger.
The Steelers are going to have to split the first team practice reps between Ben and whomever is going to be the starter for the first four games. There is not going to be time for the other two to get a lot of first team reps simply because there are just not enough to go around.
So, regardless of what Mike Tomlin says, even if he is not going to officially announce who the starter is until the preseason starts, watching who is getting the other reps, opposite of Big Ben, and that is the man Tomlin has decided will lead the team for the first quarter of the season.