That's actually legitimately what the Canucks DO need. They need better coaching, a top 4 defenceman, and a completely revamped bottom 6. Given the flat cap and Green's expiring contract, coaching and bottom 6 are two areas that the Canucks can quickly revamp, but they need a solid 3C to build around.
So you think the best way to go about this type of transformation is to trade away the only regular bottom 6 player on the team with offensive upside and a cap hit under $1million dollars. I also disagree with you on the team needs. Right now the Canucks have 4 top 6 forwards (9,40,6,53) if the Canucks want to be a cup contender they need 2 additional top 6 wingers. As for the bottom 6, sure Sutter plays that type of role, but at $4.38 he is paid as a top 6. How do the Canuck's easily rebuild their bottom 6 with $3x2yrs owed to Roussel and Beagle, $4+ owed to Sutter and $6 million on our 14th forward. On defense we have 1 top pairing guy (43), 1 2nd pairing guy (88) and a whack of third pairing/AHL players to round out the defense.
So in your scenario we add cap over Gaudette, get older, lose years of control, lose any offensive upside and do nothing to correct the current issues the team is having.