That is true. And it's all possible.
I personally never get tired of looking around Azys Lla and certainly wouldn't object to exploring more Allagan Compounds. (Still hoping that Nero's Aetherometer was picking up a weapons hanger of some kind below the Labyrinth of Ancients and we get to explore it)
The main problem with determining the long term fate of The Remnants of Allage is that we only recently discovered any reliable information at all on Allage when the tomestones were deciphered. Prior to that any information prior to The Age of Endless Frost (5th Umbral Era) was unreliable at best and complete speculation at worst. And even with the Tomestones information we lack most of the history of the 3rd Astral Era, The Entirety of the time between the 4th and 5th Umbral eras are still unreliable, and everything 3rd Umbral Era and Back are completely unknown pre-history and as much myth as history at this point.