Several months ago, Google stopped requiring users to make Google+ accounts to sign up for other Google services like GMail or YouTube. As of today, your YouTube comments will no longer be posted publicly to your Google+ account automatically.
However, YouTube channels and videos are still linked to Google+ accounts. This separation will come later. DO NOT DELETE YOUR GOOGLE+ PROFILE IF YOU DO NOT WANT TO ALSO DELETE YOUR YOUTUBE CHANNEL.
Google claims that this decision will help to remove things from Google+ that aren't "essential to an interest-based social experience".
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