What does being activated have to do with promotion?
You don't get to promote any leaders just because they have
a certain seniority. But of course, if a leader started below seniority 4 and now has 4 or better, he will have to have done something to get there, which is when he becomes available to be promoted.
IIRC gaining 4 levels of seniority, regardless of at which level the leader is then at, also triggers promotion.