I suppose one thing you could try, off the top of my head, might be the following:
Install Edubuntu 14.04, minus any/all of the educational packages, depending on what you want, but including the LTSP element.
Once installation is complete, open up a terminal and type the following commands:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
If all of that goes without a hitch, you will have ended up with Ubuntu 16.04 with LTSP
At which point you could install the Ubuntu Mate desktop over the top if you so wished. Or, if you wanted a pure Ubuntu Mate experience, purge Unity and then install Ubuntu Mate desktop.
I'll bet a pound to a penny, however, that the distribution upgrade will break LTSP!
If you decide to have a go, let me know if it works!