Given that there is a future (where Risette is from and where Latoya gets the water) the question is where it is situated in the wider scheme of things.

Because if that's teh future of the current timeline it would give away that the Sept-Terrion is eventually defeated and tehy would all know this.

There are of course different options but the way I see it:

If the Sept-Terrion was always primed after the Great Collapse (like by the remnants oft he time civilization) a future with very advanced technology where some kind of major cataclysm has occured would have never come to pass.

So there is an original timeline where the Grand Reset has not occurred around the time it usually happens.

Which means that in the original timeline there are at least 50 additional years after the present time.

Eventually, someone obtained control of the Sept-Terrion of Time (that would probably be a relative of Agnes but in a wildly different setting -- perhaps the first Sheena) and decided that the only way to allow humanity to exist in some state is to trigger a rewind once humanity is able to deploy WoMD (it's frequently said that Calvard's tech level allows that).

Because they didn't want to kill everyone they transfer the minds (as Hamilton suggests) perhaps into the Grand Archive similar to the nuke professor. Novartis was perhaps able to hack the process, allowing him to move to the next loop.

This means there could be other people from these 50 years, obviously the Grandmaster. Perhaps she had the Aureole back then (this explains the deleted text from Sky III) which allowed her to create some protective phase space.

Van spoke with the Grandmaster because he is the 7th Anguis.