What I can see from the Lucee Downloads is the following:
- Lucee Versions < 6.0 had at one point in the past the Tomcat Version 9.0 bundled and since then all the snapshots have been bundled with Tomcat 9.0: also 5.4 LTS including all snapshots come with Tomcat 9.
- Lucee Version >=6.0 have usually been published with Tomcat 8.0, but the Releases up to 6.0.4.10 with Tomcat 9.0. All the snapshots around that versions are still bundled with Tomcat 8.0.
To me it looks like the publishing of Lucee >= 6.0 have never been really been deployed automatically to be delivered with Tomcat 9.0. Maybe the Releases up to 6.0.4.10 have been deployed manually (also the missing snapshot date suggest something like that)
I’m pretty sure the Lucee Team has this well in mind: There have been work going on regarding the deployment lately, but looks like it’s going to be published with Lucee 6.2. See: Jira
However, there is still the workaround available by downloading 5.4 LTS and just switch the lucee.jar. To update Tomcat 9 to latest version, the following post may help: Upgrade tomcat 9 server wont start (RESOLVED) (its for ubuntu, but the procedure should be very alike on other OS)