Welcome to community.
I'm not quite sure about your question. You said you've removed the OS. Does that mean you've remove the whole VM(all vm files) or just remove virtual disk from VM Settings?
If you removed all VM files, I think the disk space will be returned. But if you've just remove the virtual disk from VM Settings, you've removed the link between *.vmx and *.vmdk.
The *.vmdk files still exist on your host.
