Integration of Openfire Jabberserver ... https://www.igniterealtime.org/projects/openfire/
Openfire is a real time collaboration (RTC) server licensed under the Open Source Apache License. It uses the only widely adopted open protocol for instant messaging, XMPP (also called Jabber). Openfire is incredibly easy to setup and administer, but offers rock-solid security and performance.
honestly, to large degree it sounds like advertisement
while Plesk team has no intent to integrate OpenFire, it can be delivered by any party through Plesk Extensions (https://ext.plesk.com/help). Feel free to develop the integration and submit it into Extension Catalog
The idea is good though ;-)