That would completely disregard the point of the roulettes. The goal of the roulettes is to fill in groups for people who are attempting to run certain dungeons. It's so when I queue up for Cutter's Cry, I don't need to wait for 3 other people who also want to run Cutter's Cry. I wouldn't count on roulettes being completed with Trusts. It's more likely that they'll add the ability to run trusts with multiple people (i.e. you and your friend with 2 trust members) which would be a good addition.
