Hi,
Assuming you have configured ONTAP to sync with an NTP time source and issues such as kerberos clock skew only occur if the time between the storage controller and domain controller is greater than 300 seconds (5 minutes) different then I don't think this will present risk. If the time is correct on the NTP source then Data ONTAP will transition through the leap second event.
https://kb.netapp.com/support/index?page=content&id=3011978&locale=en_US
Hope that helps
/matt
If this post resolved your issue, help others by selecting ACCEPT AS SOLUTION or adding a KUDO.