This does not mean that we are born gay. Our brain is not fully developed at birth. Therefore, the discovery of neurological differences between gay and straight people does not mean that we are born gay. LaVey himself even admitted in 1994 that just because homosexuals and heterosexuals have different neurological differences, it does not necessarily indicate that they were born this way. He also admitted that the brains he studied had died from AIDS. He could not rule out that the neurological discrepancies were not caused by the disease. 
Additionally, neuroscience is an area in which we still know very little. The correlation between regions of the brain and behavioural traits has not been proven beyond doubt.