The TN you have reference is focused towards an issue with the 'top of the infomation store' and the overall structure of your Archive.
The icons for calender or sent items are directly managed by, surprisingly, the value of the 'foldericon' field. so you need to confirm the correct 'rootidentity' then find the correct folderid, then run an 'update' script to change the specific value for the exact folder in the exact archive that needs changing.
There are probably quicker ways through SQL, for example if you return all rows with a foldername = 'calender' which have a foldericon value of < 2. that will show you how many archive calenders are affected.
I say this but I would seriously think about opening a support call if you are questioning how to change a value in SQL.
The icon issue has been seen in very few cases where, mail migrations or where other mass mail movement has occured, the migration process seems to affect the trigger that we look at to assign the correct folder icon to the folder when running the archive.
End story, if you are good with SQL you want to find the correcct folderid which is having the issue, using the archiveid and rootidentity.
Or if you want to blanket job it, something akin too
use enterprisevaultdirectory
Update dbo.ArchiveFolder
Set FolderIcon =2
Where FolderName = 'Calendar'
AND FolderIcon = 0
As always, before making manual edits to your EV SQL configuration, stop any archiving procedures, backup your db and system , committ the changes, test it works, then start archiving again.
