Hallo !
I bought my ticket with DERTICKETSERVICE.DE
They send me an e-mail as UW venue change from the E-werk to the Paladium in which they said that the ticket will remain valid for the new venue (this is not an e-ticket but a ticket that I received by the post office).
Perhaps you can ask directly to E-Werk :
info@e-werk-cologne.com
Best !