Yeah, Tower of Voices 2 being a new story would probably be for the best. It's a shame since ToV is the 4th longest Fantasy series on the site in terms of chapter depth, but it'll probably be less daunting for new readers. Although one thing to consider is: what happens if run 2 doesn't go nearly as long as Yulia's? Let's say, for argument's sake, MC 2 Bad Ends 30 chapters in. Does 31 pick up with the new MC? Do something similar to Monster Isekai and those types of stories, and put a new option below chapter 1 for each MC? Just want to be prepared for when we hit MC 5 or 6, especially if the difficulty goes up (which I wouldn't mind, we got our win, I'd be fine taking bigger risks on future runs). Besides that little bit of futureproofing, should be fine to do this. Longtime readers will know a lot, but the new readers will know as much as the new MC does so that shouldn't be too much of an issue.
Similarly, would we want to make a new Voting Thread for ToV 2? 140 pages of posts is probably as daunting as 446 chapters.