I don't think any coach, especially a brand new one going up against teams who know most of the personnel on his team (like Coach, for instance), would be very wise to let everybody know who he's thinking of playing where. This also applies for players who are being tried out in different positions; give them a chance, but no need to discourage them if you decide they belong where they were.
I'd keep my mouth shut and use coach speak 24/7 in such a situation.
An aside: I'm reading Israel's The Dutch Republic right about now. A great (and really long) book that reads like a novel in places. He has an explanation of why William I was called "William the Silent". It didn't have anything to do with him keeping his mouth shut; he was the life of the party most of the time. Instead, it was about the way he never discussed what his plans were with anyone until he put them in action. Sounds like he would have made a great football coach.