But the timeline of events doesn't add up.
The original dragon was already in Unova when it was founded by the two brothers.
The meteorite crash came later, Drayden and Juniper say it happened around the time the Dragonspiral tower was built and the DNA splicers were created. Lacunosa was also already established since they had to build walls to protect the city.
Juniper even suggests the meteorite was just Kyurem's stone form.
So the Lacunosa folktale couldn't have been about the original dragon, by that time it would have been about Kyurem splitting from Reshiram and Zekrom. And obviously Kyurem isn't from space unless the dragon decided to fly to the moon and back.