The fact that latinos (more specifically puertoricans) helped create hip hop culture is undeniable. There probably weren't many puertorican mc's, but there were definitely alot of puertorican djs, graffiti artists and breakdancers.
You could even argue that dominicans helped shape the evolution of hip hop in the late 80s and early 90s due to them being largely responsible for the crack epidemic in NYC, which, believe it or not, inspired a whole era of hip hop and some of the best rappers are a result of these circumstances.
Maybe latinos didn't participate DIRECTLY in the creation of hip hop (except puertoricans), but they definitely influenced in some way shape or form the culture. Remember that hip hop was birthed in the Bronx in the late 70s and the Bronx had a huge puertorican population that lived in the same neighborhoods as black people and went to the same public schools. Saying that latinos had absolutely NO influence in the creation of the culture is a straight up lie.
Now, music genre's like funk, soul, jazz, blues and rock and roll are 100% black. There's 0 influence from the latin community in those genre's. Unlike hip hop, these genre's came from 100% black communities.