My own preference is that we not redraft. You can build a team in any league on the Board, and with Unmanaged trades, you can do built it no matter how many unowned teams there are.
The drop in trading is partly the result of the maturing of leagues, where more teams have a game plan and want to hold the good players that support that plan.
That said, if there is a groundswell of owners who want to start over and have Formation Drafts, I would give up some of the teams I have been building to see it happen.

Dave N