Earlier quoted context omitted.
You could have multiple failsafes, and after a part of them fail, you dehibernate automatically. We have systems that work well with such approach - planes being the most notable example - multiple redundancies, and when sth critical fails, you land asap. Works most of the time.
And then you wake up on the moon in a lava tube too early with a partly failing system and hope that everything else still somewhat works? With current technology level I definitely would rather bet on humans.
If you wake up too early in a lava tube on the Moon, you then use the tools and spare parts you hopefully were smart enough to pack and repair your cryo-pod and then go back to sleep.