They did! In the Support Desk, there is a message under 'Item Restoration - Fantasia Potion' stating:

'Before going through the details of our one-time item restoration service, we would like to remind you that there are plans to make the Fantasia potion available again for players in the near future as an optional service.'

So it will be in the Mog Station I am assuming. They just haven't given any further information now and it has apparently been confirmed for months