Mavic freehubs are known to squeal but it is not because of the bearings. The freehub uses a nylon bushing and one bearing while most freehubs use multiple bearings and definitely no nylon bushing.
The nylon bushing squeals when it is dry. Mavic recommends taking the freehub off and lubing the bushing (with oil, I personally use chainlube) every 1500 miles or so.
So if this servicing hasn't been done with your freehub, you get the dreaded squeal. Also, if it hasn't been lubed properly it will wear out and you have to replace the whole freehub OR you can replace just the bushing. There are aftermarket bushings available on eBay. Just search for "mavic bushing" on eBay.
Mavic will never tell you that you can replace just the bushing as they want you to buy a whole new freehub for around $70.
So the next time your Mavic wheels start to squeal, remove the freehub and do some maintenance.