Oracle 12c. Is it possible to export a TDE encrypted table using expdp / impdp to a database without TDE / wallet enabled?
TDE encrypts the data at rest only. As soon as the data is read off the disk, it is decrypted. 
So if you need to copy the data to a new database instance you can just do a CTAS or IAS over the db link. 
You should be able to use datapump also, but you have db link between the two database it is the easiest solution.