It should be fine for normal use cases when used with error correcting codes without any active scrubbing.
According error rates for ECC RAM (which should be at least by an order of magnitude comparable) of 1 bit error per gigabyte of RAM per 1.8 hours1, we would assume ~5000 errors in a year. The average likelyhood of hitting an already affected byte is approx. (5000/2)/1e9=2e-6. So that probability * 5000 errors is about a 1.2 percent chance that two errors occur in one byte after a year. It grows exponentially once you start going a past a year. But in total, I would say that standard error correcting codes should be sufficient to catch all errors, even if in hibernation for a whole year.
Who wouldn’t? They are doing some of the most advanced rocket science on the planet. Of course, trusting corporations statements and research is an entire topic of it’s own. Taking Elon Musk seriously on the other hand…