Yeah, there has been a movement in recent decades to redefine racism, sexism, etc. As only applying to stereotyping, prejudice, and discrimination by a person from a dominant group toward people from a marginalized group. To some extent I get that--that is why anyone ever started caring about racism etc.--and language evolves. If we as a society decide that is the only set of valid definitions, I'll go with it, because I care more about the struggle for equality than about the words used in that process.
That said, my issue with this usage is that it is imprecise and bundles some extra judgments. This use of racism requires an extra assessment of the power dynamics between the groups each of the parties belongs to (and sometimes identifying that is a quagmire itself). I'd prefer keeping those judgments separate. For example, maybe responding to this racist troll by saying that some kind of racism cause and deepen harm a lot more than others, and he is ignoring that fact due to his own racism.
I think that is a reasonable take. It is s huge jump, in many ways, so I believe it is much more dangerous than other capitalist "innovations".