Something someone pointed out which makes may shed some light:
The wine bottle Wanda pours in the trailer is titled "MAISON DU MEPRIS". 'Maison du' is French for 'House of' and while Mepris is a made up word it seems, it does begin with M. This is likely a nod to the House of M storyline from the comics, which IIRC, includes the exact storyline I predicted above! The comic line goes into a lot more complex and crazy stuff, including she Thanos-ing most (all?) existing mutants, but I doubt we'll get all of that in the show for obvious reasons.
~Thylo
The word you don't recognise is French for "scorn" or "contempt".