For anyone played since ARR, you would know that Vana'diel do exist in FF14's timeline and confirmed to be not one of the 14 shard.
This is evident in Black Mage's request line and first Black Mage relic weapon.
During the Black Mage soul stone the soul stone is referred to as "The Gem of Shatotto"
Base onMeteion's report, she basically confirmed there is no trace of life form left outside of Etheirys. Is this solid evident to say Vana'diel was destroyed already?