As far as I know the last version was released 7/9/13 version 5.1.20513.0 http://www.microsoft.com/getsilverlight/Get-Started/Install/Default.aspx
If the above link shows (Your ready to use Microsoft Silverlight) then yes you can simply Hide the reoccurring update. Note if Silverlight is Disabled you'll be prompted to download it/ Alt+TA
or Uninstall it all together if anyone wishes to.
There has been a string of Windows updates that have been reoccurring lately/ ie10-Office Outlook and now Silverlight ?
Very odd indeed only Outlook on my end but that was corrected without Hiding the update = just left it in the queue and now it's gone.
I did remember one site which uses Silverlight