If a user were to theoretically serial commit necro-threadery - as in hop to to several ancient threads that haven’t actually been locked and arbitrarily cold-start them - would they be violating terms of service? It’s for scientific advancement of course.
If its over 3 months old its considered a necro if its over a year way to old and will get a warning.
Necroing in and of itself isn’t against any rules, per se.
But it is heavily frowned upon, and could result in action taken. Ctrl+F “necro”.
Necroing with the sole purpose of adding nothing to the conversation is actionable.
In Customer Support it doesn’t even have to be that long. Some posts a couple days or a week old could be considered necroed as the issue being posted about originally was addressed by the Devs/QA. Something like a temporary connection issue due to an ISP outage or a DDoS attack. Or an issue with a hotfix that gets repatched quickly because it caused an exploit.
Players having what appear to be similar issues aren’t always having the same problem. The recent issue with guild banks appearing empty or not having enough gold that was caused by an issue with the realm connection process looks the same as the one caused by misbehaving addons.
I’m thinking it would depend on the thread and the forum it was necroed in. Something in the realm forums might not have the sensitivity that Customer Support does. It would also depend on what is posted to necro the thread. “Bump” would likely result in action. Actually posting something relevant might not.
The word “several” here carries a bit of weight. When people spam necro threads to cause disruption - such as finding all the threads about X topic and bumping them to flood the front page - that ends up with an account action.
The EULA is intentionally vague about what can, or can not, be actioned because players can be creative in ways to be disruptive.