It's not racist, because it doesn't say anything about the worth of the human or their rights. In fact, if you refuse to categorize and measure, because you consider this in itself to be evil, you can't actually cater to this specific person.
But I’m afraid that in practice, races aren’t biologically defined.
I believe that no, and that they are categorized by ticking choice in a form. This is instutionalized racism but people in the USA have it so internalized since childhood they can't seem to be able to understand it.
But saying it never matters whether you are black or asian or whatever useful term is for the european-like mix in the USA, is actually going to disadvantage the very people this stance wants to protect, because it does ignore, that they are going to react differently to pathogens, food or medication.
But claiming the US 5-races system is more significant as a categorization of people than other dimensions for health issues is definitely racist, and is propagating that systemic racism.