Like raspberry pi and lattepanda does pine64's rockpro64 has mechanism to automatically reboot or (boot as soon as power is plugged in )in case it shutsdown abruptly ?
That depends on what "shutdown abpruptly" really means
The couple hard crashes I saw on mine, it just rebooted on it's own...
If it's not rebooting and you want it to, try checking your OS settings. Some include options specifically for restarting after power failures.