For instance: a guy level 105 needs a respec. The quest would demand drops from Bilbiza but also Chillberg Island. There, while doing the quest, he could also meet people from the same level as he to play with (maybe?) and also gain a little bit of a decent XP for his level.
Holy cow that is the exact opposite of a good idea. You don't see a problem with "respec requires mats of XXX level" and "getting XP while farming them"? If the person out-leveled that mat-bracket, then they'd have to start all over with their farming!