Hey there!
I noticed in the launch version of the game removed this feature:
In the trial we were able to have a partially full party, yet still be able to be the predator when using matchmaking.
This option was great so we could still play as the predator while playing with friends rather than needing 5 people for a private match.
This would be great if the feature could return!
Thanks for making this game. Keep up the hard work!