I think there's a small amount of truth to it especially when people target someone like Luna Oi, but at least for now it's in the vast majority of cases an equivalent of chud or lib etc. and historically was a term made by mostly white British leftists to make fun of other mostly white British leftists, not something to describe groups of people in the global south.
I think this is pretty similar energy to right wing ppl / libs last year claiming using gusano is racist, obviously the people who get called gusano are almost always more reactionary than people that get called tankies outside of maybe like 1 or 2 of nazbols, but I think neither in his words are frequently racist, and it's a weird energy especially as Ben Norton is a white American guy and seems more about wanting to own the people who use tankie as an insult than it is about making a stand against any racism happening.
https://unofficialbird.com/BenjaminNorton/status/1609586255641169921#m
we should say it's racist anyway so libs say it less