Honestly SE is pretty good at avoiding retcons in FF14. Certainly a lot tighter than Warcraft tends to be. Its worth noting that for much of the lore, including the lore books, they leave themselves some wriggle room by presenting the lore as if it was from an in world source. Thus there is never a guarantee that anything you don't personally witness is 100% right. It also means you often need information from several sources to form a true image of events that play out. Regardless, the lore team puts a lot of time and effort into ensuring things make sense or at least there is a logical explanation about something being different to what we thought it was before. Changes done right can feel like discoveries rather than retcons and that can spill into all sorts of interesting speculation.

Its worth noting that there was a thread on this forum after the book came out where Koji Fox, one of the people involved in the creation and translation of the book, interacted with us to identify inconsistencies and errors and provide corrections. Poor Koji felt rather bad and embarrassed about the errors in his translation but it is bound to happen occasionally.