Confusion about FreeBSD-Release of Host and Jails

[dyseptical]

Hey guys!

My current setup:
- A TrueNAS Core Host that was installed with 13.0-U4 a few months ago and updated to 13.0-U6 in the meantime
- 5 Jails, 4 of them Plugins (AdGuard Home, Emby Server - Stable, OpenVPN Server and Nextcloud)

The TrueNAS Core Host is currently running FreeBSD 13.1-RELEASEp9, same with the 4 Jails that are Plugins.
(I created the 5th Jail manually a few days ago with FreeBSD 13.2)
I've lately stumbled on the issue of pkg throwing an error about a kernel mismatch in the Plugin Jails.
There are already forum posts about this (for ex. this post), but I'm quite confused about something there.
According to the above post and Wikipedia, FreeBSD 13.1 is EOL. FreeBSD 13.2 is still supported though and upgrading the Jails to 13.2 should solve the pkg issue.
I wanted to upgrade all the Jails to 13.2, but all of the "Plugin Jails" failed to do so.

After a bit of digging this is were I think I stand:
- The Community Plugin Jails most likely can't be upgraded because the maintainer hasn't updated the repository or plugin index - not an issue, i will redo all of the Jails and set them up myself.
- The Nextcloud Plugin Jail can't be upgraded because i tinkered with it - i can also set that Jail up myself.

However, my Host is still sitting on FreeBSD 13.1.
Will the Host "upgrade" to 13.2 if i upgrade all of the Jails or are all 13.0-U6 TrueNAS Core Hosts currently running FreeBSD 13.1?
Do i have to somehow manually upgrade the Host to 13.2?

I found this post but it unfortunately only added to the confusion...

TrueNAS 13 is not at FreeBSD 13.0, 13.1 or some other specific release. It follows the releng/13 branch which means "any 13.x at some point in time".

Why do I get the FreeBSD 13.1-RELEASE-p9 XXXXX-XXXX TRUENAS on the Host's Shell then?
Running freebsd-version on the Host also gives me the same Release Number...

I'm really sorry about the weird questioning, coming from Linux Servers FreeBSD can still be a bit hard at times...
Maybe someone can clear my confusion about this.
Thank you very much in advance!

Show : System Hardware

TrueNAS Core 13.0-U6 running on
Fujitsu ESPRIMO with an Intel Core i7-4770 and 24GB of RAM
SATA Boot SSD, PCIe M.2 SSD for Jails
2x Seagate IronWolf 6TB ST6000VN0033 for Main Data Storage

 

[Jailer]

As long as you jails are of the same major version or lower than the host then you are fine. You can't run a jail on a newer major release than the host as the jail would require a newer kernel than the host can provide.

For example a 13.2 jail is fine on a 13.1 host. A 14.0 (current FreeBSD release version) jail will not run on a 13.1 host.