Thanks for using Fusion.
I am not working on this feature, so I don't know the reason of why Linux doesn't support clean up from UI. However, there is a way to shrink disk in Linux VM if you installed VMware Tools.
Open terminal, run:
sudo vmware-toolbox-cmd disk shrink <location>
e.g. sudo vmware-toolbox-cmd disk shrink /
To know more help: run:
sudo vmware-toolbox-cmd help disk