It's actually a good idea.

Wait aren't namekians already non binary they don't have pp

Depends on the translation, but it's noted by Dende that all namekians are male.(English version both Z and Z Kai)

But it's actually a stab at the cluelessness of Hollywood executives.. the last line is a reference to one thing they actually get right, but only to an extent.
As genderless is not part of the non binary when it's a natural occurrence.. much like Hermaphroditic mutation is not part of the Non Binary standard.