After the N-VA left the federal government last December, the Francophone liberals of MR are the biggest fraction at the federal level. It was more or less a logical choice to choose someone from that family. "And let's not forget that the MR lost two big names: Didier Reynders and Charles Michel who both move to Europe. There is the need for a new star. Wilmès can take this place and become this star."
But there's more. "Wilmès is the only one - at least within the MR - to speak Dutch, and she belongs to the camp of Charles Michel. It was Michel's explicit wish that Wilmès would take over from him." Another reason why Wilmès made it - apart from her own merits, of course - was that if somebody else would have been chosen to succeed Charles Michel, the puzzle would have been more complicated between the different parties. Now, a Francophone liberal is replacing a fellow Francophone liberal and the balance is being kept.