25 year olds are the perfect guys to trade when you want to rebuild. It may shock sensibilities, but that's true for 22 year olds as well. If you are honest that you need to acquire elite end talent via the NHL Draft and the most likely way to do that is to pick high, you also want to be surrounding them with a lot of other picks in the same time and play a numbers game in terms of seeing which players emerge. The issue with the RFA players is (a) they get in the way of the "tank", (b) their future UFA contracts eats up some of your cap space that could be spent when your high draft picks come of age and used as appropriate to build the ideal roster around them, (c) their personal timeline based on sub-section b gets in the way of the overall team's timeline.
The caliber of player we're talking here is usually going to be available at the then ages that they will be at when the team is theoretically coming out on the other end of the rebuild, a critical point that I think gets overlokoked. I'd be much more hesitant to trade 25 year olds for picks if there wasn't a salary cap/teams had unlimited resources. In the draft/cap world, getting everyone on the same timeline makes a lot of sense. The idea that you'll ride out your 25 year old through the rebuild and have them come out on the other end of it is usually more wishful thinking from GMs that have a tough time admitting something like that is a better move for the 10-year outlook of the team.