Troy not coming back is a safe assumption unfortunately. He hasn't reprised a non-union Japanese game dub role in almost 4 years or taken any new ones in a bit over 5.
Laura Bailey is 50/50 though. She does return to older roles when she can make it work, but doesn't take new non-union game roles and will bow out if she has a schedule conflict. Travis Willingham and Liam O'Brien also have decent chances of coming back.
Yuri Lowenthal, Michelle Ruff, Erin Fitzgerald, Kirk Thornton, Jamieson Price are all safe.