The Spring framework recently announced their roadmap towards integration of Jakarta EE 9+, which includes the namespace change from "javax.*" to "jakarta.*".
Is there already a Jakarta EE 9+ roadmap for Quarkus?
Not only Quarkus, most of the Jakarta EE servers planning to move to Jakarta EE 10 once it's available. Jakarta EE 9 is kinda of tooling and vendor check to endure everything looks after jakarta namespace.
Wildfly - https://www.wildfly.org/news/2021/09/27/WildFly-Changes/ - WF produce previews until for Jakarta EE 9 and switch to Jakarta 10 line until it's finally available.
TomEE - https://lists.apache.org/thread/bm35j3t9p049g30sb0swotwo0pzfloc3 - might release TomEE 9 as short lived version, once TomEE 10 is out, TomEE 9 will not be supported.
Payara - Payara 5 uses transformer tool to support Jakarta EE 9 namespace. Payara 6 will support Jakarta EE 10 natively.
Quarkus - Since Jakarta EE 9 is not bringing any new feature. Quarkus will wait for Jakarta EE 10. - https://github.com/quarkusio/quarkus/issues/21574#issuecomment-1003597405
Apache CXF - version 4 migrates to Jakarta namespace.