True, but SSD manufacturers say the drive should hold its data for at least 10 years after the drive has reached its recommended lifetime (these drives were well past that).
That sounds like a specification they got from a high density Flash datasheet which I saw recently; it was 10 years typical with no guarantied minimum. My own tests show that high density Flash has a retention of months. I assume SSDs can get away with that because they can perform background scrubbing while powered but the USB Flash drives that I have tested do not and they forget their contents before a year is up whether powered or not if they are not actively used.
Based on old datasheets involving floating gate memory which did list minimum retention times of 20+ years, I have the feeling that the manufacturers do not specify minimum retention because a low duration of months would look bad.