Yeah. The advice applies mostly to "Let's get married when you return!"-style relationships, where the couple met in meatspace, dated in meatspace, became a "couple" in meatspace, and then have to separate for a long period of time and things will all be better once they get back together... all of which often fails horribly.

From three data points, it seems like those that survive the first separation might have no trouble with subsequent ones, or at least that the risk of repeat separations is greatly diminished (though if one cheated the first time, they'll likely be cheating the other times too, AFAIK, but that's 1 more datapoint + folk wisdom).

7/7 relationships I've seen that were started in cyberspace, stayed long distance for a while, then met in meatspace, then had to have a long-distance period, all survived (and are still healthy couples to this day as far as I'm aware). Seems like the filtering effect applies long before anyone ever meets eachother for cyberspace-started relationships, especially for long-distance ones.