Akane knew about pre-VLR’s events throughout the course of 999

999’s game had been a requisite for VLR’s, which had been a byproduct of what occurred at the Mars Test Site

Akane had to have contacted someone from the future or performed some sort of jump–Akane most likely has some sort of guide or someone she’s spoken to

but time travel canonically starts with Sigma

Sigma pioneered those jumps

so

:^)