The 50 year anniversary hype is everywhere.I personally agree with the last paragraph of the article:

'He also mentions that he finds the 50th anniversary of hip hop mile-marker a bit disingenuous. The birth of an entire movement can’t be attributed to one act. “I’m definitely not a person to shit on hip hop’s anniversary, or its founders,” he says. “These influential figures are extremely important. They changed the world and they deserve recognition and they deserve compensation. One hundred percent, underlined, big cap, bold letters. Capitalism, industry, commerce require neat stories. But we also have to be like, is this the whole story, or is this a convenient story?” Likely the latter, and it’s incomplete.'

There's certainly precedents in terms of black political poetry in music (The Last Poets, Gil Scott-Heron) and there was clearly a need for the disenfranchised to have a voice, but there's the other aspects such as graffiti, dancing and DJing that all came together over time.