March fixpack was last planned fixpack for 7.1.0 and 7.2.0 firmwares, end of service is 9/30.
7.6.0 was first LTS (Long Term Support) release for DataPower:
7.7.0 is continuous delivery branch.
If you do not want or need (eg. by APIC) to stay on continuous delivery branch, you should NOT upgrade to 7.7.0 firmware.