Soulcalibur V has some additional fighters, but you won’t find Heaven or Melrose on the character select screen. These characters are fan-created quick battle NPCs. Judging from the screenshots, Heaven looks like he has Voldo’s move set. Hinata has Tira’s weapon (and probably her fighting style!) and Qatif appears to be either Siegfried or Nightmare.
Tekken series producer Katsuhiro Harada is in Soulcalibur V too, at least as a quick battle character, and he has Devil Jin’s fighting style.
Edge Master and Agol are playable characters, though!