Road tyre tread is designed to allow a certain amount of water to be transported out of the way from a smooth surface when the tyre pushes into it, aquaplaning is where a tyre is overwhelmed by the volume of water and is in effect waterskiing on the water.
MTB tread of course totally different, is designed to allow the tyre to dig in and grip on an uneven loose surface, a bit like studs on a snow tyre.
A road tyre that is not aquaplaning but is loosing grip due to wet surface is merely slipping, technically it is probably experiencing hydrodynamic lubrication.
To minimise aquaplaning on the road you probably want skinnier tyres - more concentrated weight will cut through the water better and less 'ski' area. The issue for TdF riders will be that they are not comfortable/experienced in sliding and their bikes like modern F1 cars are not designed for sliding, their high psi fast rolling tyres have a kife edge of grip in corners, so they want wider tyres to make their bikes more slip tolerant with a lesser kife edge of grip --- and to make them feel more confident.
That's my tuppence anyway.