Each character should have the option to automatically complete all quests (without rewards of course - just like any skip we have in the game) that were already warband-completed. You could debate whether this should exist in current content, but at a minimum this should be applicable for all low-level/legacy quests.
Why? Because there’s a ton of broken phasing junk throughout the world that blocks your alts from getting to things, mobs, friendly NPCs, etc. unless you plow through mountains of questlines on each toon. It’s annoying.
“But people will complain that they skipped quests!” Skip options are already a thing. This is nothing new. It’s only bigger and completes quests that were already completed on the account. It follows the warband philosophy with respect to player time, etc.
“But I don’t want this!” Fine, you don’t have to use it. Tada! That doesn’t mean stop others who want to use it.