Did you even read the post? They say that they believe that including the decryption key is not violating anything as its only a small portion of the software.
It was taken off Steam because Valve asked Nintendo how they felt about it - Nintendo obviously didn’t like it, so Valve said Dolphin needs to be removed unless they can get permission from Nintendo.
Dolphin Blog: What Happened to Dolphin on Steam? (dolphin-emu.org) angielski