With inaccessible respecs being a thing of the past and blacksmith services now being free, I think there's room to have these.
Multiple concurrent auctions, or smaller time intervals of time between each auction for:
Heirloom Exchange: These are always going to be capped at 1 LP or below in gold value anyway
Title of Nobility
Training Lessons
New auctions:
Temporary Unique Items: Example would be Boulder on a Stick/Looney Toons Axe/Green Felt Hat, though current holiday items could be excluded, especially tournament prizes like the crown/engraved stuff. These would be untradable/no-armory flagged, transferable between characters on one account. Item vanishes or gets automatically transferred to whoever wins the next auction on a weekly interval.
Weapons Training: Respec on WPF only
Limited Heirloom Exchange: Exchanges that only work on +1 or +2 items, instead of +1/+2/+3. This would not replace the original heirloom exchange.