I hope there will be a 'Republic Commando 2'.
But they won't be "imperial commandos", unless they change the storyline to a different squad.
Delta and Omega squads immediately disobeyed Order 66, most probably because they didn't trust Palpatine? Not too sure why they disobeyed it but hopefully for a good reason.
But ideas for a second game? Well the most obvious answer is something along the lines of:
Although Delta Squad's advisor is sworn to secrecy about the real nature of their mission on Kashyyyk. The advisor tells them, and they work to bring down the Empire from within. Sev survives but is captured by Trandoshan slavers and the hunt is on as Delta Squad follows in Sev's tracks, perhaps meeting rebels and imperials alike?
It could work maybe.