That's not true. Typically any server with a watch functionality will have a mutable reference to the data that's being watched. When you change that data out

That's not true. Typically any server with a watch functionality will have a mutable reference to the data that's being watched. When you change that data out you're both changing the mutable reference, and also deallocating any memory that was previously used. One could separate these two steps, moving the watched data to another variable that's dropped in another thread, if you wanted.