For this question, assume that the virus does not mutate.
Can survivors be expected to develop immunity? Why or why not (what is the thought process)?
The CDC FAQ indicates that they do not know:
Q: Can people who recover from COVID-19 be infected again?
A: The immune response to COVID-19 is not yet understood. Patients with MERS-CoV infection are unlikely to be re-infected shortly after they recover, but it is not yet known whether similar immune protection will be observed for patients with COVID-19.
As good as CDC is, I would expect that there are other excellent institutions and individuals that have insight.
CLARIFICATION: a survivor for this discussion is an COVID 19 infected patient that survives the infection. My understanding is that there is no reason to believe that the uninfected would develop immunity.