They can do it like WoW, where the achievement gives a mount only if completed before the next tier is out. This made people rush for it before the mount is gone forever. Title and token should remain as rewards for those who clear at anytime.

Honestly, I don’t know why people are against rewards.
“Don’t reward those that worked hard to clear content.”
“They do it for the challenge, not rewards.”

I mean sure, but giving them something is not going to break the game.