Deadline is reporting that due to concerns over the coronavirus, production on The Prom has been shut down for the time being. They were apparently set to wrap shooting over the next few days, but one of the last scenes was set in a high school, which was closed for health concerns.
The good news is that 1) they were close to finishing up, so not much left to shoot, and 2) the tentative plan is to resume/finish in mid April.
The way the whole planet seems to be shutting down, however, it's anyone's guess when production will continue. Regardless, I fully expect this to be released in 2020.