It sounds like you want to be able to generate language with the same basic meaning as the original but without whatever bias was there. I'd recommend starting

It sounds like you want to be able to generate language with the same basic meaning as the original but without whatever bias was there. I'd recommend starting by trying to detect the presence of the bias first. Language generation is a very difficult problem in general and this is an especially difficult instance of it. Even detecting bias will be challenging because of how subtle a phenomenon it is, but it's much more tractable than rewriting what was said to not include the detected bias.