Airprint is a series of protocols, not really a software. Xerox does not make an application to make non-airprint enabled machines work via Airprint.
Xerox does make Xerox Mobile Print, but that is an entirely different method of printing from mobile.
It would be much more likely for Xerox to make an application that worked in conjunction with Mopria, since Xerox is partnered with them and it is essentially tyhe same thing as Airprint, just not owned and marketed by Apple.
As far as I know, there is no intention to develop such a software for either protocol by Xerox. There are as you mentioned many 3rd party applications that do so, such as Airprint Activator and Printopia.