"If I would like to remove my child from that class and put her in a class with a different teacher, I cannot do that because it would be akin to asking to have her moved from a teacher because they are African American or Hispanic."
That's because that is basically what this is the modern equivalent to. A couple decades ago you would have been threatening to pull your kid from a classroom because the school dared to let an African-American or Hispanic person teach it, and rather than accept people for who they are, like your religion (if you're a fundie) and basic fucking human decency asks of you, you lash out at them simply for being different.
And, of course, the "think of the children" bit to try and pretend the bigoted assholes are the "good guys" here. As has been stated, your kid's not going to have trouble accepting the "oh my male teacher's a female now" bit. Not unless you indoctrinate him to be a bigoted asshole like yourself (this is not an invitation to indoctrinate your kid).