Common meaning:

Agreement with the traditional male and female gender roles and that sex between the two genders is normal.

Hidden meaning of the Equity religion: 

Dominant culture oppresses marginalized groups by pushing a false reality of what normal sex is.

Discussion:

Equity teaches that the dominant culture promotes heteronormativity in order to oppress marginalized groups. By promoting a false reality of what normal sex is, the dominant groups damage those who have non-traditional genders.

Equity believers have started using words like heteronormativity to communicate that there is no such thing as normal. They use this as part of their attack on the norms and values of Western society. It is no longer good to be normal because that is heteronormative and that is bad.

In reality, there is no such thing as heteronormative, only normal gender roles of male and female. Anything else is an aberration from what human biological bodies were designed to accomplish in the production of offspring.

The Equityists are using the term heteronormativity as a trick in order to try and destroy normality.