Filenames may seem trivial but it's an important part of a planned post-production workflow, especially when archiving. Tremendous problems have been caused by lack of attention in this area.
The filename example you gave is 83 characters long. There are two filesystems used by M-Disc, ISO 9660 and Universal Disk Format (UDF). Standard ISO 9660 supports up to 31 character filenames. There are extensions like Joliet (Windows) and Rock Ridge (Unix/Linux) that allow for longer filenames, up to 64 and 255 characters, respectively, and support for additional characters and file attributes.
UDF (Universal Disk Format) supports up to 255 characters, and is generally more flexible and better suited for modern systems. If the backup M-Discs will be burned on a Mac, I'm assuming it would probably use UDF.
If the MacOS files use Finder tags or info stored in the Finder comments field (as seen in Get Info), I don't know how that is supported on M-Disc UDF, so you should probably test that.
Re renaming files, as Zabobon said, you normally should not do that. You also want to avoid any duplicate filenames.
Re filename strategy, my personal preference is do as little as possible at the filesystem level and as much as possible in FCP. E.g, I've worked on large projects where we simply added a unique 5-digit incrementing serial number to each camera file to ensure uniqueness, then laced those in a folder tree by ProductionName/ProductionDay/Camera+Operator/files
Then we used the FCP import option Keywords: From folders, which automatically keyworded the files on import with the folder names. That system worked because 100% of our post work was in FCP.
Another approach is using a dedicated Asset Manager such as CatDV (Now owned by Quantum):
We currently use a method similar to yours of assigning long filenames. I don't really like that but there is no good choice except for using a dedicated asset manager. Filenames are at least durable and understandable without further decoding. But we immediately assign those filenames soon after offload, before using them in any production. Changing filenames after ingest usually causes problems.
An inexpensive approach is using NeoFinder to catalog the media which is then searchable across all offline drives. I think NeoFinder can also handle Finder tags. I'm not sure about M-Disc compatibility:
If imported media is keyworded in FCP, those keywords can be exported as Finder tags using the third-party utility FindrCat:
Basically do not assume anything will work and test any workflow at a small scale before you commit to it.