The PA announcer isn't obligated to announce the end of a penalty
at all, and I don't think they do in arenas where I've seen games.  It
should be pretty obvious to just about everyone that the penalty is
over, as long as the penalty time is posted on the scoreboard.  If they
want to curtail the chant, they could just stop announcing the end of
penalties.
     I don't know why this should be considered an "alarming trend,"
unless one simply enjoys hearing that particular chant.  It isn't
censorship, and I'm sure the crowd is creative enough to devise other
contexts in which to use the same language with equal gusto.
 
-Glenn