You do know, private servers cannot be hosted in North America because Blizzard/Activision would sue the living crap out of them, right?
Not wanting anything to do with Private Servers... You must have read their big wall of No incorrectly. Blizzard said they will never release old content. Below is one of their many excuses. They don't like private servers and will do anything to not have them around. There is a reason you cannot promote these servers on their forum bud...
3. The original game code does not exist in that form anymore. All the old data has been replaced, with the newer data which was not saved (archived) for later reuse. It was over-written and destroyed. “There is no switch to flip on the realms to roll back years of patches and changes…” In keeping with the sentiment in expressed in #2, above, it’s gone, never to return. Even if it were “recoverable” by other means it would still require lengthy and expensive rewrite.
In short, Blizzard is a company and they feel older content servers wouldn't bring enough income to keep them running, or bring the old code back. Private servers would detract
some people from playing their game at $15/mo at least per player deterred. Now, tell me, if you are in the financial Dept of a big company and seeing something that is illegal that could be potentially losing you money, would you allow it? twitch is hosted in the US, so it has to follow DMCA. Blizzard owns the rights to WoW's content and can tell twitch this streamer has to stop streaming old content and promoting something that is illegal in the US and twitch has to oblige.
TL/DR:
Blizzard will do anything in their power to hinder a growth of a private server, and building roadblocks on twitch matches their track record of what they have done to US private servers.