Yes, it is.
Please note, section 1 "License Conditions" in the yEd Software License Agreement says "... install one copy of the Software and use it as an application ..." (emphasis mine). This means you are not allowed to use yEd with an automated software distribution system unless you get express permission from yWorks GmbH to do so. If you intend to automate yEd installation, please contact the yWorks sales department to negotiate terms.