Laughable because it is incorrect?
Or laughable simply because it has a lot of holes in it (i.e. is very incomplete)?
Well, it's incomplete and also appears to be inaccurate. For one example: he mentions the reason for Shantarakshita's obstacles and exile as singularly being an outbreak of smallpox that was blamed on him. And then Guru Rinpoche was invited, and "drove out the demons who had caused the smallpox".
This when compared with Dudjom Rinpoche's account seems reductionist and inaccurate. To quote from the translation of his text:
[Shantarakshita] granted the eight vows to some, but when he taught the doctrines of the ten virtues and of the eighteen psychophysical bases, the savage demons and deities of Tibet became angry. Lightening struck Marpori [the "Red Mountain", site of the present Potala Palace] and the palace at Phangtang was swept away by a flood. The harvest was destroyed and great calamities befell the country. Evil ministers said, "This is due to the practice of the doctrine. The master should be banished to his own country."
It is too much to ask me to transcribe the whole chapter, but let's just say there are plenty more details that elaborate a history that Berzin completely ignores.. By saying there was simply a smallpox epidemic and that's the thing Guru Rinpoche came to stop is absurd.
That's one example, but it appears that Berzin's sense of history and basic information are highly questionable -- at least when it comes to the Nyingma / Ancient Tradition. Perhaps his accounts of Gelug history are more accurate, I wouldn't know.
In any case, is it the consensus—despite the Gelugpa Alexander Berzin's recommendation to—that it is totally unnecessary for a Dzogchenpa (or aspiring Dzogchenpa), who has not yet recognized Nyimed, to meditate in the dark, that is outside the context of Dark Retreat and Dream Yoga?
I simple don't know. For a confident answer you would need to actually ask a Dzogchen master who has extensive knowledge of the breadth of the tradition-- since it is possible at least that in one or two Dzogchen lineage streams there may be some practice like the one he describes. Regardless, this seems like a scholastic question for you and not one relevant for your practice -- for the simple reason that we should really only be practicing that which we have transmission and instruction for-- not getting an idea from a website and trying to accomplish it on our lonesome!