Of course he is, he's taking a stance that the views of Gray and Keys was prehistoric and the implication being that his views are more open and progressive.
Music can be interpreted in many ways if it is indeed deliberately vague or allegorical. However, aspects of modern R&B and rap are neither vague or allegorical and are overtly sexist and homophobic. Even at a minimum the endemic culture of treating women as sexual objects in that genre is in my opinion far more odious than questioning a woman's ability to run the line effectively.
In addition, there are at least three incidents where Rio has engaged in "roasting" and you can hardly suggest that this is a positive attitude to women as equals.
It's all well and good stating sexism has no place in sport when it would appear that you are part of the culture promulgating and continuing the sexist culture.
Your talking about aspects of an entire genre of music, but you're not being specific. Seeing women as objects of sexual desire and stating such is hardly a crime, if anything it is just honesty, it doesn't actually mean that women are viewed as nothing more than sexual objects of desire.
As for Rios alleged penchant for roasting, it is a sexual act between consenting adults, so what?