A plugin that did something like that would be pretty easy to come up with, I think.
It should also be possible to catch the
save command in an event listener and determine if it's about to resurrect a deleted file and either block the save or redirect to a command that asks you for confirmation first, I would think.
I'm not sure if either of those already exist though. Generally when I work with Git and I'm moving between commits or branches, I tend to make sure that everything is saved and up to date before I execute any commands. So if a tab appears unsaved, I know it's because that file is now considered deleted.