An Idea would something like 'Streamermode'. Rust has something like that, they hide all the "important" informations about the servers so Streamsnipers cant find the server the easy way.
That would depend on how many servers they bring out and would require a lot of servers, else the streamsnipers could just jump between the servers and "brute force" which server they are playing on. Also, since you can't change server, the streamsnipers would only need to find them once.
Only blizzard has the authority of controlling their systems. Twitch is an advertisement platform for games as much as Google's search engine for websites.
Concerns of these systems are already considered by server and authentication engineers. They design systems for more than a twitch crowd. There will always be a population that will naturally form around influencers. Blizzard has already stated that there will be sharding of servers at the start to maintain stability of zones.
My opinion?
No there won't be any special cookie scenarios outside of those who represent or are a part of the Blizzard studios.
edit:
Influencers are a risk and will not be endorsed by Blizzard without incredibly strict NDAs.