Copyright issues were there forever no matter what. Thats how law is working. You are not allowed to use copyrighted content on your own and especially make money out of it. I don't see it wrong banning or just blocking social accounts. As you don't follow the rules you need to suffer.
Indeed is not morally correct as SRO is dying and this could have been the only thing that kept SRO alive untill now, pservers.
Let me tell you about these copyrighted craps, I've been working online spamming different industries with shitloads of social media accounts and got shitloads of bans and yet, here I am. (With more than 5k accounts lost within last couple years).
Copyright infrigement is a thing but nailing Twitch category just because you want your game to be pointed out clearly is a big desperate scream of attention. I see it as a propaganda and as people said above in thread, they open EU race soon so they needed some attention. Silkroad always bring attention doing dramas, thats how the game works after all XD. No drama no fun