Yep. The text says the kensei weapons you choose count as monk weapons for you. Since it doesn't say otherwise, all of the properties of regular monk weapons apply to your kensei weapons, including the ability to attack with Dex instead of Str. One thing to note, for all you Monk/Rogue multiclassers and monks with the Defensive Duelist feat, just because you can attack with Dex, it does NOT mean these weapons gain the Finesse property. If they already had it, like a Shortsword or Dagger, they still do. But weapons like a Quarterstaff or Longsword cannot suddenly trigger Sneak Attack etc.