Last year the three big shows ( NAMM, SFF, SB ) all happened in less than a month. So i set up one thread to cover all three..
My recollection of that was much like you suggest, jiffybox, companies did use one show to set up for another, and were less concerned with trying to hold back.
Of course Superbooth is the bigger show for things of most interest in this forum, and there were definitely plenty of companies that just picked one of the shows for their big presentations.