From a post on Reddit:
Hi
The role was closed for new applications earlier this week, so yes, there won't be any new applications accepted until it re-opens. We only have a certain number of slots each role every year, once they're filled then we close it. You can still register for it via the role page on the RAF Recruitment website.
If you already have an application in the system it will be processed once we can get to it. It's taking longer than normal due to the covid 19 impact on the entire process etc.
Kind regards
Adam
RAF Recruitment