https://www.jenkins.io/blog/2022/06/28/require-java-11/

says:

Agents

For best results, it is recommended to run agents with the same version of Java as the version used on the controller. Use the Versions Node Monitors plugin to verify that agents are running a compatible version of Java.

Running the Jenkins remoting process on an agent with Java 11 or 17 does not imply that you need to run your builds with the same version of Java. You can continue to use any desired version of Java for individual builds.

I just upgraded zabbix from 5.x to 6.x. The order for zabbix upgrades is:

1. Ensure agents will support destination version (for 6, that meant 4.4+, but generally one has everything synced before upgrading, so it's a non-issue)
2. Upgrade server
3. Upgrade proxies
4. Eventually upgrade agents

The important thing about the sequence is that it's well documented.

The order for upgrading jenkins appears to be:

1. Ensure that the version of java that agents will run is at least as new as the version of java that the server will run
2. Upgrade java version on jenkins server
3. Upgrade jenkins
4. ...

Anyway, if there's an explicit order that should be followed, and the above order does appear to be the only order that will work reliably, then it should be documented in at least the release notes for this version, for the lts, and in the above linked blog announcement.

And note: the upgrade order should be before the instructions for Upgrading java.

In the blog, that step is:

Upgrading to Java 11 or 17

 
The order item should be before that mark.
 
Also, if you're revisiting the blog, could I encourage you to include a Table of Contents at the top?