Hi @Paulciloquent,
I think you should ignore those for now and check the updated situation (MP). Both the article of Kevin and the post of Graham are referring to the SQL free Space Monitoring, defined within the old management pack. Now there is a new MP, which has been re-written:
Microsoft System Center Management Pack for SQL Server
Please go through the guide and check what it exactly mentions.
One more thing - it si recommended to create "Index Rebuild" Job, so that the Indexes can get rebuild overnight:
What SQL maintenance should I perform on my SCOM 2016 databases?
This will also be interesting to you:
System Center Operations Manager (SCOM) Management Group Performance Optimizations
and
Possible increased unused disk space when running SCOM 2016 on SQL2016
Hope I was able to help.
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(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Stoyan