This is mostly anecdotal, but If word of mouth holds up, I think ratings will definitely increase. Scream Queens has been the topic of the week in my Uni cohort and the largely positive reception has encouraged others to catch the post streams. A friend of mine told me that everyone he works with has been raving about the show and he is going to jump on board, because he doesn't want to miss out.
Edit:
It's probably too early to discuss whether a second season will follow, but it appears
Fox have possibly registered and trademarked a follow-up title: "Scream Queens:
". It's a direction I'm sure most of us are expecting Scream Queens to take.