I'm kind of entertaining the idea of a little appearance plot twist - like MacGyver showing up bald or Riley getting pregnant or Jack with either bleached or red hair
But we all know CBS has a different idea of plot twists and surprises when it comes to Season premieres. Also, Lenkov kinda already spoiled the appearance plot twist (Mac wearing a beard).
Last Summer, there was a bit of secrecy going on as well for a while. Remember Justin filming on the Halloween set; stating he can't show us who's on set with them? We all thought it was probably David as Murdoc, but it was Isabel as Cage. They did a pretty good job at hiding her for the production of 6 episodes. We didn't even realize it when George spilled the beans by posting a photo with her.
So... in S2, the "big" changes were a new regular (Cage), new love interests for Bozer, Jack and Riley (Leanna / Dawn / Billy), a new male recurring who's kinda famous (Elwood) and two female recurring characters (Jill/Leanna), a big character reveal (Oversight) plus guest stars with ties to the Original (Bruce McGill / Michael Des Barres).
I'm assuming if the budget didn't change much, they will follow the same line.
We already have a new love interest (Nasha?) for MacGyver and will delve more into the other love interests and their stories (Leanna / Billy). So I'm guessing also maybe more family members; maybe from Jack's or Bozer's side? (Jack's sister, Bozer's parents). They could add a "famous" guest-star into those recurring roles.
Not sure which other guest star with ties to the original could show up. They kinda already used the best-known ones (since RDA has no interest and Dana Elcar is not available). Last "big" one would be Teri Hatcher, I guess.
I'm assuming the big mid-season or season-finale plot twist will have something to do with Oversight.