On a related note regarding FFXIV's Salina and Desch, my mind keeps going to the odd revelations we got from Heaven-on-High (particularly the
follow-up quest), seeing as it name-dropped them again and now the larger CT plot has become so central to the game's story.
The Onishishu "seek the lost knowledge of the Allagans, that it may benefit the peoples of the modern world". Their founder knew Salina and Desch. The recorded conversation at the Pine - still overly cryptic - touches on the same themes that ring through Shadowbringers and was surely written in combination with it.