In all fairness, a good chunk of the "name" SHIELD characters got pretty much written out of MCU continuity with the 70-year gap from WWII until now....let's face it, the modern MCU won't include Dum-Dum Dugan, Gabe Jones, Izzy Cohen or Dino Manelli, who would all long since be dead (or at least 90-100 years old). And they won't likely use any of the actual supers like Spider-Woman (any version) because (a) they'll want to reserve the possibility of developing those on the *big* screen and (b) it'd run contrary to Joss' theme for the TV show, which is about normal humans interacting with a superhero universe.
Still, I'd like to see some "name" agents show up, even if it's just one-episode cameos. It's surprising that Sitwell (Max Hernandez) from the movies wasn't offered a role.
I think we will see a good amount of Sitwell, he just isn't part of the main cast. I imagine that he will be a re-occurring character that shows up every few episodes. Additionally, I'd bet that we get cameos from Danvers, Woo, and Quartermain just to let the audience know that they are around but most likely out handling other issues in the MCU.