I think it was a Sheldon Brown article that debunks tread on a narrow road bike tyre as only a ‘sales gimmick’. Tread there isn’t needed as the tyre is too narrow to aquaplane unless you can hit an impossible speed. A wider motorbike tyre has to hit something closer to 100mph or something, a narrower road bike tyre cuts through water like ‘a knife through butter’. Im tubeless these days which originally ruled out Mitchelin Powers but I ran them before on my good bike (and still do on my TT bike and commuter, Power TT and Endurance) and would have no qualms about their lack of tread, its more to do with the compound and there’s more of that in contact with the road. Good choice and enjoy 
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