You won't lose anything. Ubuntu stays ubuntu, but if you want extra support (e.g. Professional level usage) you have to pay to get it earlier and for longer.
The last Ubuntu I ran was with Xfce, with the whole Unity interface being where I lost any interest in anything that Canonical has a hand in steering--adoption of Snaps nailed that coffin. I still have some Ubuntu server cloud VMs which will switch when next rebuilt.
