Thank you for contacting Intel Embedded Community.
The TN suffix is related to leaded devices instead of the suffix EN related to lead free (RoHS compliant) devices. Due to this fact, they are related to the RoHS migration process that is unrelated to functionality changes. You can confirm this information on pages 6, 2, 3, and 5 of the http://qdms.intel.com/dm/i.aspx/0CAC6A57-0C53-4379-9CDF-E57FB452469C/PCN105304-01.pdf Product Change Notification (PCN) 105304-01, also on page 10 you may find the cited part numbers.
By the way, please keep in mind the information stated in the attached Dear Customer Letter (DCL) and the http://qdms.intel.com/dm/i.aspx/7C715FEC-C598-444E-9EFB-2750B98F7956/PCN106013-01.pdf PCN 106013-01.
We hope that this information may help you.