2021 will see the release of a two-part Batman animated film adapting The Long Halloween story by Jeph Loeb and Tim Sale in 2021.
This article that leaked the movie listed these actors as part of the voice cast:
Troy Baker
Jensen Ackles
Naya Rivera (Could she get a tribute in the film?)
Titus Welliver
David Dastmalchan
Jim Pirri
Amy Landecker
Matthew Gray Gubler
Katee Sackhoff
Fred Tatasciore