Look like only 1 league has filled so far. May need a bunch of fillers or consolidate some leagues. Hopefully most are just waiting to nearer the deadline.
There is no real advantage. It is simply that many put things off until the deadline. After today they risk the possibility of losing their spot in the league...
IMHO, future leagues should be overbooked as was done successfully the past two years. With an extra manager or two initially assigned to each league, leagues fill much faster, and nobody has to wait for the no-shows and stragglers except the other no-shows and stragglers.