The roadmap through December is great.
Personally, I think to keep the PvE element alive they need to be constantly updating ARCs, adding new ones, buffing weak ones, etc. Lore wise it would make sense that the robot overlords learn, adapt, and get better over time and it won't turn the PvE into a snoozefest you ignore while trying to hunt people to PvP. For PvE in an extraction shooter to be interesting they have to be a real, genuine threat that is just as or more deadly than other players. If the arcs weren't as scary as they were, i bet people would be a lot less friendly.