It is set around 700 years after the Old Gods are slaughtered, so it's way, way after Gelus and Pario.
The time line shall go: Gelus > Pario > Contego (WIP) > Rescisco (WIP) > 700+ time skip > WRBC > GSLH (WIP)
The full game will contain a codex to drop hints at the lore to come in the rest of the mainline.