I feel like this would be easy to test, at some cost. Buy N SSDs from X manufacturers. Fill the entire disk with random bits (/dev/urandom), read it back and compute a hash. Wait A, B, C, and D durations. After each duration, read the drives again and compare the hash.
Bit rot is definitely a problem with HDDs, especially as their bit densities increased. I've heard that bit rot on SSDs also became a thing as well after they started moving from SLC to MLC.
I'd be interested to see a study on how prevalent either of them are.
I recently powered up a 2012 Macbook Air with SSD after 7 years and had no data loss.