My assumption is that they’re gonna operate with the idea that this season is the final one until they get the green light that it isn’t. Both Stana and Nathan are signed to a one-year contract which means that they’re both gonna have to renegotiate at some point if season nine is in the cards.
So yeah, I’d think whatever Hawley and Winter have crafted probably is meant to standalone within this season. Obviously I’d expect they are hoping to keep the show going for longer, but the last thing you want as a showrunner is to introduce a story (or stories) that you can’t tell fully in the time allotted. We’ve all had a show that we loved that was prematurely cancelled and we were left to guess at what the future would have been for a character, you know?
I do think the show needs a new multi-episode villain, and I do think introducing that person in the season premiere is just as effective as whatever alternative you might go for. I have no idea if that is what will happen, but two-parters are kind of ripe for a longer than usual story format or even the introduction of a longer story arc that might repeat later in the season.
Personally, if Stana (a girl who goes to Mongolia on vacation and has been known to carry throwing knives in her car for the hell of it) classifies this as nail biting then I’m pretty pumped. That girl has never led me astray with the show before, so I’ve got no reason to start doubting her now. And, really, Susan Sullivan used the term extraordinary, and I don’t think a woman with a career as varied and as long as hers is gonna toss that term around lightly. Plus, if you don’t trust Susan I might personally kick you out of the fandom because I really am questioning your life choices.