I donˋt know what someone told you in 2013 and why we are now suddenly talking about Cubase Elements, but if you installed and activated elements trial version, it will no longer run after the trial period has ended thats how it has always been.
You can install whatever you want on whatever computer, but it will not run with a valid license. If you donˋt buy the elements version, you will not get a soft license, therefore you will have to run your elements version with your „Pro“ USB elicenser.