Nah, mhio is saying that the blog post has a typo:
> Postgres 13’s gen_random_uuid() which generates a V6 UUID that’s secure...
gen_random_uuid gives you a version V4 UUID, not a V6 UUID (it's even in the code comments in the snipped included in the blog). I don't believe Postgres even has a function to generate a V6 UUID - which, indeed, would be a bad idea to use as a source of randomness.
