ATT lists the "Wild Preserve Circuit" race in Waking Shores to be on the npc for "Wild Preserve Slalom", the correct npc quest giver is 190503 with coords 42.6, 94.4:

https://www.wowhead.com/npc=190503
https://www.wowhead.com/achievement=15720

This appears to be correct in ATT now. Was fixed in 6f95c6e#diff-8093d94f5a42575f5d7d9f54f5ab4d87c5b911fafcea0a500ad9c3807fcd824dL1630.