You are correct - Towers is no longer on the 40-man roster:
http://toronto.bluejays.mlb.com/NASA...n.jsp?c_id=tor (although Figueroa hasn't been added yet).
I'm not sure if it's automatic that an outrighted player is removed from the 40-man roster, but since outrighting a player and removing a player from the 40-man involve the same thing (exposing them to waivers), I guess it leaves that option open.
In other baseball news, Michael Barrett has been suspended for 10 games for his sucker punch on A.J. Pierzynski (and he's appealing, because he's thinks it's too harsh) -- frankly, I think he deserves double that. You just can't punch someone like that, even after a hard (albeit clean) slide. For some reason Pierzynski was fined by the league for his "part", which is just stupid in my opinion...