Let me see if I can explain.
Ever since Catalina, the boot disk for a Mac is not what you see in the Finder (or even at command-line sessions).
The boot disk actually consists of two volumes - a System volume and a Data volume. On Big Sur and later, the actual System volume is hidden - macOS instead creates a snapshot of it and generates a cryptographic signature for the snapshot in order to make sure it never gets altered.
The System volume is read-only and can only be modified by Apple’s macOS installers. It contains all of the things that should never change without an OS upgrade.
The Data volume contains everything else. This includes most of your apps, all user home directories, device drivers (including kernel extensions) you may have installed, etc.
At system startup, the System volume (or its cryptographically-signed snapshot, the “SSV”) is merged with the Data volume to present one single virtual storage volume to you and your applications. Aside from getting some inexplicable errors if you try to modify a file on the System volume, you shouldn’t normally see the difference.
(The APFS container holding the System and Data volumes has a few other volumes - Preboot, Recovery and VM, but they are purely for internal use. The preboot and recovery volumes aren’t even mounted most of the time. You can safely ignore them).
There should be something like this on your external drive as well. One APFS container holding five volumes - two of which are combined to form the volume you and your applications see.
As for the name that appears in Disk Utility, that’s the internal name of the volumes and containers. It doesn’t necessarily match the name shown in the Finder as the mounted volume’s icon, because the mounted “volume” is actually composed of two internal volumes. Renaming it from the Finder may not push that name into the underlying volumes - because there’s no particular reason why it has to.
I don’t know about the “Update” container you’re referring to. Howard Oakley’s articles don’t show one. They show an Update volume belonging to the Apple_APFS_Recovery container (only present on an M1 Mac’s internal storage device). Is what what you’re seeing or is it something else?
I wouldn’t worry about if anything broke. If the system is running and working, then I wouldn’t worry about it. If you want to try and understand what’s going on under the covers, it might be interesting, but it is complex and unusual so don’t assume anything is broken just because it doesn’t look like what you were expecting to see.
If you want, feel free to open a terminal window and type the following two commands and share with us the output:
diskutil list
diskutil apfs list
These two commands will show you the various containers and volumes that your system has. We may be able to help explain what you’re seeing based on that information.