The original Dante leak, which is the same leak that got all the DMCV info right, didn't mention any other characters being in or not.Also didn't all of the other Dante "leaks" either say A. He would be in base B. Had characters who ended up not being in at all or C. Didn't have a character who did end up being in?
Overall my thoughts are that it's within the realm of possibility that a CG trailer was already in the works/"done" in some form even if he doesn't release until next year. I'm skeptical though.