Most players in the top rankings of the last few tournaments were running into an issue where after hitting a certain point threshold, they began seeing seed times and low ranked teams exclusively in their match options. I wrote into support and got a response:
To his point, I can now see matches against unshielded players in my range. Just wanted to share that because they really are working hard to make sure that people can make moves through the rankings at the last minute strategically instead of just shielding ad nauseam.