No, not necesarilly EU. For example, if they had used RotS as a way to introduce the Empire's willingness to use BHs it would have been a good bridge to ESB. Having already used Jango as the Clone template, but having been killed by the time Order 66 happens, Palpatine could have used other BHs to lead Clonetroopers against Jedi. Aurra Sing, a young Boba perhaps, Bosk, Zuckus... whatever. Would have been kinda cool.