But that’s because it’s intentionally hard to tell if it’s feudalism in a capitalist hat or capitalism in a feudalism hat. That’s what oligarchy is.

No, (modern) oligarchy is a term we may use for the political structure that is supported by capitalism, which is the mode of production. In feudal society, oligarchs were nobles with landed power. In capitalist society, they are just a small subset of the capitalists.

It is not feudalism because the economic surplus is not extracted (primarily) through land ownership and tribute, but through the property relations of wage labour.

Yes, we can see neo-feudal structures within a late stage capitalist economy.

No, that does not preclude capitalism as the mode of production enabling those structures.