Not really. Depending on what level you started as and how good your items were, level sync can give you stats that exceed what a character in that dungeon's level range would normally be at.
Regardless it doesn't help characters trying to level up when a tank can't hold threat because his threat output isn't high enough.
Also anyone saying "tank is undergeared" is ignoring the fact I have seen tanks in level appropriate gear do their mechanics right, and still lose threat. It's only tanks who are level synced down to the dungeon that seem to have few issues pre-40.