Should people planning to buy a Ryzen system hold off until this is fixed?
Under Windows it worked flawlessly even with the old BIOS.
I've been happily using my 1700x on my personal machine for months without much issue (except when as noted above, the issue was induced with very very high CPU load, manually and in a controlled manner).
Unless you do very CPU heavy work that lasts several minutes or longer (like kernel compiling, chromium compiling, autotools, starting electron apps), especially when you run gentoo (most likely), it should not be an issue.
I do a lot of dev work myself, so I do compile often but a short compiler run hasn't ever induced this bug and longer linux kernel builds suffered more from my inadequate cooling solutions rather than the CPU having bugs.