If the argument is that SM2 is successful because it limited it’s scope to execute a smaller number of features well, I don’t think that holds up. It took on three different types of games and (imho) executed merely okay. What more could they have added? Open world? MMO?
I think the more plausible explanation for the sales is that it’s Warhammer, it’s pretty, and SM1 was good.
It becomes useless as evidence unless you can establish authenticity. It just makes audio recordings more in a class with text documents; perfectly fakeable, but admissible with the right supporting information. So I agree it’s a change, but it’s not the end of audio evidence, and it’s a change in a direction which courts already have experience.