I don't believe this idea makes any sense. This is like saying that if you spray hot water out of a hose, it somehow cools down as a result of being accelerated. Or, that if you transport a cup of hot coffee at high speed on an airplane, that it somehow becomes "de-thermalized".As these positive ions accelerate down the steep potential energy drop, they exchange the high (electrical) potential energy they had in the photosphere into kinetic energy – they gain extremely high outward radial velocity and lose side-to-side random motion. Thus they become "de-thermalized." This is because in this region of high radial acceleration, the movement of these ions becomes extremely organized (parallel). Their temperature, which is just a measure of their random motion, drops to a minimum.
I could accept that cooling might occur as a result of some type of adiabatic process, though I haven't worked out any of the numbers relating to the assumed densities and temperatures and so forth, in relation to the Sun. But there's no basis for accelerated ions to "lose side-to-side random motion" purely as a result of acceleration.
As a disclaimer, I'm completely convinced of the ubiquitous and fundamental involvement of electromagnetic effects in the operation of the Sun, and the rest of the cosmos as well; I believe this is undeniable by anyone open minded enough to look at even some of the overwhelming evidence. And, Donald Scott's great web site was in fact my own first eye-opening introduction to Ralph Juergens and the matrix of EU concepts. But I believe the notion of "dethermalization" in this context is an error.