I didn’t listen to this, but from the description of the conversation I question whether she really did dismiss the rumors. Seems to me that she created a strawman - this idea that people think they’re divorcing because they can’t believe hat she could make her own decisions as selfishly as she wanted. Actually, thinking she might divorce him is by its very nature an affirmation that she can make her own decisions. The reason people questioned is because the Obamas seem to be living a separate life and don’t seem to enjoy each other. And if the description of this conversation is accurate, she didn’t address that - only created this strawman.
For almost ALL of their married lives, the Obamas have lived apart, lived their own, very separate lives, and this really was an arranged marriage...for political reasons.