Exactly, the % given is only a value in relation to a set target value for each level/division. The first year the target value is 25. So if a player has a speed of 25, he will have 100% in speed. Season 2 the target value is 30, so a player with an ability of 25 in season 2 on a promoted team will no longer have 100% but the ability it self is the same, ie 25. The player does not get worse from one season to another.