I said it because I am an intellectual who knows things. Without UDG, there would be so many plot holes in DR3 that it would be insane. Also, you get that sweet sweet character development for Toko/Jack that she needed.
I'm at the end of UDG at the moment and i love the game- and also yEs Toko's development was amazing. There was an easter egg in V3 that mentioned a UDG 2. But i'm not sure how that would work. Either way I love the game. I also wanna see Komaru and Toko in more DR stuff.
I'm not sure how long it'll be until UDG2 or any DR game comes out tho since Kodaka left Spike Chunsoft to start his own company. If UDG2 was a thing, I kinda think it would take place either between UDG1 and DR2 or between DR2 and DR3 Future Arc.
Also, Komaru and Toko play a role in DR3 Future Arc, so you can see more of them there along with the Warriors Of Hope (except Monaca is on her own and the rest of the Warriors are with Komaru and Toko).