Update could appease brands joining boycott by increasing ability to monitor offensive content.
Civil rights group outlines case against social network as it organizes ad pause in July.
Video service debated whether to host brand showcase, but in the end decided on customized performance.
Platform discusses role in current racial justice landscape and nods to its election coverage, without mentioning president.
Meanwhile, Google forecast to lose revenue; Nestle rethinks offensive brand; and Mixer's streaming setback.