Car won't run past 60mph

Would that guru submit that your torque converter is only generating foam in the fluid beyond a certain rpm, due to lack of load ? Maybe. That is the type scenarios he was suggesting.

It's possible and a thought I had.
Water and air both will separate out after sitting, so that would be the tell tale.
Air does is fairly quickly, and I didn't see a separation line in the fluid in the bottle so am assuming it's water.