This article gives me big "progressives don't know that a penis is not a vagina" energy.
Except for a very small lunatic fringe minority, progressives generally aren't saying genetics "don't matter", they're saying that they shouldn't. Someone might have a neurological learning disability for example but that doesn't mean you should disregard them but accommodate them to the fullest extent possible.
Sorry for the following tangent but I promise it's relevant:
There is a lot of "progressivism" in the media where "not saying color" is portrayed as a solution to racism but this has become so ubiquitous that even conservatives have started copying this line. That's because it doesn't actually address the underlying impact of racism, it just hides it and makes acknowledging its connection to "color" a social faux pas.
At this point progressives are the ones saying "race absolutely exists and is tied to someone's physical reality", where they disagree with race realists is the degree to which race is a useful concept outside addressing racism (where it is necessary because you can't talk about racial discrimination without acknowledging that people are being grouped into racial categories). Same with sexism, sex and gender differences. That something is a "social construct" doesn't mean it can't interact with physical realities -- "species" is a social construct but it's obvious almost any way you look at it that there is some kind of utility in grouping creatures into "hamster" or "human".
She mentions autism and deafness as examples for genetic differences but it's progressives who are the ones pushing the concept of "neurodiversity", i.e. accepting that there ARE differences between the way human minds work and that we should be more accepting of people whose minds work differently (e.g. some autistics being bad at reading social cues but intuitively engaging in systems thinking). Traditional mainstream liberalism again pushed the opposite approach, of treating disabled people not as disabled but "differently abled" (again, a viewpoint now often propagated by conservatives when celebrating individuals who "overcome" their disability, setting an expectation for others to do the same rather than ask for affordances), thus encouraging a view that ignores their need for accommodations and not engaging with the idea of what affordances are or aren't socially normalized and what is seen as a "burden" (because it only benefits a marginalized group) vs a "necessity" (because it benefits the dominant group).
A lot of this discourse was recently fueled by companies making accommodations because of COVID that they had previously dismissed as impossible and unreasonable when disabled or neurodivergent people asked for them.
So yes, it can absolutely be true simultaneously that genetics can have a massive impact on an individual while the effects are overshadowed by in-group variation. No two people are created equal, yet we should not use that as an excuse to disempower or elevate arbitrary groups but ensure they are given equally the affordances they need to participate in society and contribute what they can. And sadly where we've done so in the past we need to compensate for the generational harm they have been burdened with.