The Ryzen 7 3800X apparently is not sampling yet:
https://twitter.com/Thracks/status/1148074445338238977
They haven't sampled simply means they haven't tested one, not that the 3800X hasn't sampled (been made). Or am I inferring your post wrong?
Gibbo said the 3800X is shipped to them and will be arriving in a few days. There are also a few 3800X reviews from Japan on YouTube.