In my experience, it's nothing sinister, just a little bit of good-natured ribbing. Although, I've never heard of or experienced males mention the Doaba v Malwa issue; it's mostly women teasing each other about their temperaments and habits. I honestly can't say whether my experiences are reflected across the board. It might be different with other people, I can't comment on that front.
Malwai women are apparently rather feisty and outspoken, whereas Doabans, supposedly, are a little more guarded yet no less lethal, lol. Just what I've seen and heard.