People should probably just stop using the term identity politics, because its almost always used in a reactionary way.
- The right uses it to fear-monger about minorities, women, and gays being elevated to the same level as white men.
- The reactionary "left" uses it for the same way, but in a "class-essentialist" context, making the claim that only relation to production determines class (and not between colonizer and colonized, enslaved and not enslaved, domestic servitude to the male patriarch, etc).
Class essentialism (really it should be called wage-earner-essentialism) is wrong: race, ethnicity, sex, and gender minority should not be extricated from poverty. Just look at the US or Latin America, your skin color is completely correlated to your wealth and life outcomes, and any analysis that tries to ignore colonialism, slavery, or patriarchal servitude as "just idpol", is doing class collaborationism with the white rulers and the mostly white labor aristocracy, who have historically been beneficiaries of the women's oppression in the household, and colonialism.
A correct definition of class should be holistic, and include those other forms of oppression, not just the simplistic understanding of class as "anyone who makes a wage." Even Engels within his lifetime went beyond that original definition from his principles of communism.
There are leftist critiques of liberal tokenism, and things like "the nation of immigrants" / "multi-culturalist" US propaganda, when the US tries to say its a "melting pot", and not a nation founded on indigenous genocide. But that is distinct from identity politics, where the entire group is targeted and treated as a monolithic entity that should stay at its current level, or dissolve their grievances and become collaborators.
Regardless, all socialist countries have had affirmative-action style programs to reduce inequalities between ethnic groups, and women's rights (hopefully sexual minorities in the future too). In this way they're doing the opposite of collaborationism, or asking groups to dissolve their specific grievances.