They don’t want a true genocide. That would be too extreme and crash civilization.
What they want is a “Soft Genocide”. i.e. Reduce everybody’s lifespan. This would reconcile things like insurance and social security actuarials that people are outliving. This “spike protein cocktail” could possibly do that. Kill thousands outright and injure everyone else on a spectrum from a little to a lot. And if it makes some infertile that’s another win for “them”.