Thank you for your patience while we gathered information to make sure our response was accurate and informative. The purple ad blocking message has clearly caused confusion for users of your experiences that rely on Twitch embeds and we apologize for not being more proactive with communication regarding a change to the embed experience.
The purple message seen in a Twitch embed was designed to address ad blocking and is shown periodically to all embed viewers. Many ad blockers modify ad behavior on Twitch and can result in abnormal behavior. This screen was put in place to help alert viewers with ad blockers as to why they may be receiving an unintended experience. This approach was the most appropriate action when implemented, however we will continue to explore ways to improve this experience for all viewers moving forward when addressing issues regarding the ads experience.