Your prediction is completely wrong.
First of all, stripes between lanes have a 36 foot gap for every 12 foot long stripe. Traveling at speed, you can’t slip much at all, I mean almost none, before your car is back fully on pavement between the stripes.
Second, your 8 inch wide tire is still wider than a 6 inch wide stripe. You can only slip sideways another 2 inches before the full contact patch of your tire is back gripping nothing but the un-striped road surface.
Never mind that all cars sold today have some form of stability control and traction control.
Wider stripes will be much easier to see in the rain when they are fresh and not worn out. The slickness is a complete safety non issue.
Your prediction is completely wrong.
= = =
Not completely.
Any unexpected car sideways slippage might cause the driver to overcompensate.
And, how about motorcycle tires?
Having spent years on the racetrack exploring the absolute limits of adhesion on both four wheels and two, it is easy for me to recognize you know nothing about the physics of traction. I won’t even bother explaining to you the different coefficients of friction between the two materials, the percentage of contact patch, or the water film thickness.
frankly, having driven a lot of highway miles in the rain, I'm tempted to discount your assurances and go with the prediction. A lot of folks drive too fast in the rain relying on their technology to save them, but the force when the contact patch on one side goes from slip to stick is significant and could cause a veer or momentary loss of directional control. Combine that with the way people drive on 101 and wow. Plus it's not all going to be gaps, they will probably stripe their solid white lines the same way.