West is West
If a Silver Age Batman is what Rocksteady is actually working on we want them to really lean into it. According to the rumours the game is going to be "stylised", which we presume means it'll star the colourful, cleancut DC heroes of that era, but we'd like it to capture the Silver Age spirit too.
For Batman: Arkham Asylum and Arkham City Rocksteady signed up Kevin Conroy to voice Batman. There's only one man we can think of that's fit to voice Silver Age Batman: Adam West. This will be controversial suggestion but we think it's right.
Now 83 years old, Adam frequently provides his voice for Family Guy, in which he plays Quahog's Mayor Adam West. We bet he'll be well up for returning to Batman.