If you're considering not doing this, either because you already got all the treasures / rares / etc in a zone, or because you use an add-on for that, you might want to do this mission anyway. In the garrison mission UI, on hover over the treasure map reward, it doesn't appear to have a value, but once the map item is in your bags, you will see that it's worth 100g to vendor. Keep that in mind if you are letting this mission expire in your garrison.
TL;DR = Map vends for 100g, do the mish even if you don't need the map.
Garrison Timer Mobile App
[Upon completion your 随从 will gain: ]
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