Avowed felt like a test for Battle.net launches and since then they've announced The Outer Worlds 2, Doom: The Dark Ages for it with Jez now hinting at even older titles being ported to it so I suppose the test has been a success? Don't think they'd bother if Avowed did fuck all on Battle.net when they already have a store.
Having said that, no South of Midnight, but the thing is they still seem to be sticking to a theme, ToW and Avowed feel like a match due to them both being AAA RPGs and Battle.net having a big focus on AAA RPGs like Diablo and WoW. Doom even feels like it sort of fits well with the overall theme of AAA Shooters, one with a mature theme, and Crash/Tony Hawk are Activision IP so meh.
So far they seem to be sticking to AAA only but ones with a genre-link to Activision IP, hence why no South of Midnight, I think it'll be true flood gates opening if they put something like Psychonauts 2 on it, Lol, South of Midnight would work too. Maybe Minecraft. Hell it's AAA but Flight Simulator on there would be "different" from what is usually on there.