The AD8494/AD8495/AD8496/AD8497 are precision instrumentation amplifiers with thermocouple cold junction compensators on an integrated circuit. They produce...
Datasheet AD8495 on Analog.com
Upon checking the bonding diagram, although pin 4 is a No Connect pin, it is still internally connected to the die. My suggestion is to keep this pin floating/no connection to avoid any unwanted effects to the amplifier.