I did not read this article, so I'll just make up some numbers I find plausible.
Somehow we need to equate entropy (or information loss) with energy. The assumption of 1eV per bit is probably ok. One electron, either changing potential of 1V or not.
So by making computations reversible, we could avoid this inevitable 1ev loss if the computation is not reversible. Nice. But if we currently burn 1keV per switch, there is no point talking about this technology right now. Let's shave off another 990eV first. Then we can think about reversibility.
You have to understand that making the computation reversible (not loosing this bit of knowledge) gets you from 1000eV to 999eV. That's premature optimization. And you all know that this is the root of all evil. Though we might keep an eye on it.