First, some history.  Oracle stopped cutting public builds of Java 1.7 at 1.7.0_u80.  However, they continued to fix security holes and made later builds available to customers with registered Oracle accounts.  Many customers didn’t care but getting these later builds was important to IT departments with security monitoring solutions and proactive policies in place.

Windchill has been holding on Java 8 for several releases but public updates are going away in January 2019.  As with Java 7, additional updates will be available via an Oracle subscription.

PTC’s tentative plan is to jump forward to Java 11 with Windchill 12.0 and then [speculative] to Java 17 in a later Windchill release.  Creo Parametric 6.0 is already reporting Java 11 compatibility.