if you read the kotaku article, they included a comic explaining its origin, which helpfully lets you know it was groomed into becoming nonbinary 
it escapes from neo cortex and the first person it meets who is friendly is a david bowie lookalike so it makes that its entire personality immediately and forever
also it's voiced by a woman (who is pretending to be nonbinary) therefore it will be heard as female and identified as such by literally everyone

it escapes from neo cortex and the first person it meets who is friendly is a david bowie lookalike so it makes that its entire personality immediately and forever
also it's voiced by a woman (who is pretending to be nonbinary) therefore it will be heard as female and identified as such by literally everyone