Not sure if you guys know already, but the PT era's gonna be part of the next Battlefront game. That in of itself is a big improvement over the last one. We see planets like Naboo, Takodana and Starkiler Base, with Rey, Kylo Ren, Darth Maul and Yoda also featuring in the trailer. So we can expect those to be new maps and heroes available.
Apparently the single-player storyline will be centred around the Imperials (or an Imperial) after the destruction of the Death Star II. However, you will have to pre-order the game to get heroes from Star Wars: The Last Jedi.
Might be part of a DLC but I doubt she'd appear otherwise. Not even sure if Ventress will appear.
The Republic has no shortage of heroes, but the CIS might have to call upon lesser known characters like Zam Wesell and Ventress,. if not immediately than in some expansion pack. Maybe Cad Bane and others. Otherwise, it's just Dooku, Maul, Grievous and Jango, which is a bit slight. Then again, they might end up just restricting the Republic heroes to Yoda, Mace, Obi-Wan and Anakin or something.
You guys are expecting way too much. Three heroes for each faction is plenty and I don’t expect any more than that. Far more important is that Dice brings back classes and allows us to play as Droidekas and the like.