From the way you described it, it's entirely possible that this was caused by a glitch on your PS4. By chance, do you use the rest mode function rather than shut down, and if so, did you have a power outage between your last play sessions, even briefly? If so, it's possible that some sort of glitch occurred that deleted your update data? I've honestly never heard of such a glitch before on the PS4, but that's the only thing I can think of beyond some sort of hard drive failure.....