It doesn't work exactly like you think it does, but it's there.
The way it works (to the best of my understanding - this isn't something I've spent a lot of time testing or anything because IMO basically nobody ever should reset their account) is that if you complete the quests, then reset your account, and at no point in there do you refresh the game window, the game remembers that you have completed the quests, and you can complete them right away upon the account-reset taking effect.
What this does not do is allow you to somehow get the 500 point quest (or any other quest for that matter) without ever having hit 500 points (before or after resetting), so there's not a way to bypass the quest entirely, but it allows you to auto-complete the quests after resetting if you completed them before resetting.
Honestly, not sure if bug or feature, but such a niche thing that it's probably not worth spending coding time on fixing.
