Well the premise of the show is that it exists in the MCU but is wholly separate from the movies. To show cameos of the TV cast might be overstepping that premise.
I bet we get some overlap. Yes, the show is going to be about what happens on the fringes of this universe but I think that refers more to story and not so much characters. The stories will be smaller in scope, but the characters, while not as powerful as the ones that have been established, I think will be free to flow back and forth between TV and film.