Yeah, I don't get why the actress playing Tory got listed as a guest. She had as much screen time as a regular, and I think they did a better job fleshing her out as a character this season than last.
As for the people I really saw as (welcome) guests yay for Chozen and Kumiko
Some thoughts of mine, in response to Martin
I don't think it was totally a filler season. The resolution to the Doyona sub-plot was definitely lazy writing at its most obvious and Miguel's healing was all unicorns and quintuple rainbows worth of realism, but certain characters (Robbie, Tory, Hawk) followed the trajectory I expected them to and even grew past where I thought they'd go. I am also a fan of bringing Kyler back. He was actually an imposing foe in S1 and with Cobra Kai training I can see him returning to that role nicely. I've been waiting for Terry Silver for a long time now, for whatever reason I feel like he and Robbie would make for a natural pairing.