When nothing can see it, it'll be removed - maybe.
The GC has a couple generations. When something goes out of scope and it can readily determine nothing has a reference, it'll collect it almost instantly.
If it can't easily determine it, it starts to get moved into a older generation. As it gets older, it needs a hard-core mark-and-sweep collector. That's what you see when the JVM memory usage suddenly drops from the peak to the trough in the SFS admin panel.
So, depending on which generation it is in, you may or may not see it get removed
