As for the hens- I'm sure the wild birds would find safe, hidden spots to stay in. Though it will be tougher on your birds to figure out without seeing it from older chickens, any that do make it through will likely be fully wild.I'm not confident a hen would survive sitting on eggs if she chooses to do so out in the woods. We'll see!
I've noticed already with the roos that 2 of them wander either alone, or on the outskirts of a larger flock. They are the loudest and most frequent crowers. Annoyingly so.
The other roos stay with groups of hens and are not as vocal.
I'd believe that about the roos. The ones protecting hens wouldn't want to attract attention to the area any more than needed. The bachelors would be more interested in calling out to attract mates.