How to create a DB Link to a Database which has failover in TNS
The referenced MOS just states the following:


Dblinks do not support TAF. This refers to FAILOVER_MODE parameter, not FAILOVER. The first parameter is about TAF, the second is about connect-time failover.
It is not recommended to use the SCAN address for dblinks in case of RAC. Instead of the SCAN address, use the VIP addresses.


Removing FAILOVER parameter will not change anything, the default parameter for it is ON. 

FAILOVER

You do not need to remove connect-time failover parameters.