It does not go beyond how socialists define imperialism, it reduces imperialism to vibes. Imperialism is a material phenomenon with definite characteristics, not whenever a country influences another. When you reduce imperialism to vibes, it certainly makes it more broadly applicable, but you lose sight of how and why it functions, how to stop it, where it comes from, etc. It's like arguing that lions and cheetahs are both cats, and that therefore cheetahs are lions.

Imperialism, in simplified characteristics, functions as follows:

-The presence of monopolies which play a decisive role in economic life.

-The merging of bank capital with industrial capital into finance capital controlled by a financial oligarchy.

-The export of capital as distinguished from the simple export of commodities.

-The formation of international monopolist capitalist associations (cartels) and multinational corporations.

-The domination and exploitation of other countries by militaristic imperialist powers, now through neocolonialism.

-The territorial division of the whole world among the biggest capitalist powers.

The USSR had interventionist foreign policy, but it was not dominating other countries nor economically plundering them. In classifying it as imperialist, you run cover for the fact that the USSR was undermining economic plunder of the global south while the west was protecting and expanding that plunder.