Thank you for the quick response and action!
Just come here to say I am still not able to reply to the beta forums, even though I was admitted to the beta last Wednesday 9/14, also as part of the Twitter lore quiz giveaway (ty, btw!). I have logged out and back in from the forums/WoW website/Battle.net multiple times. Of special note that might be helpful in sussing this out: when I log in and browse a topic, the Reply button is there, but when I click it to add a reply, the page refreshes and my ability to reply is no longer an option, and doesn’t come back any other time that session.
My situation is different, as in I don’t even see the Reply button, but I also got a beta key from a giveaway (redeemed the code). I’ve logged in and out several times, but to no avail :(. (Actually I did the relog thing a few more times and I now have access. Hopefully it works for other too).
FWiW, the advise is still the same as 2 Years ago.