Edward Snowden's whereabouts seem to be more fascinating to people than all the troubling things he's revealed. As tends to happen in cases like this, people are more interested in the character than in what he has to say.
It's quite possible that Snowden did at one point edit something on Wikipedia. As Wales mentions, he certainly fits the profile of the average editor.
However, revealing personal information about editors, information that has now been explicitly made public, "outing" in Wikipedia parlance, is against the site's rules.
Plenty of "senior" editors were quite concerned by Wales' apparent call for digging out info on Snowden, if it exists. As things tend to on Wikipedia, the whole discussion degenerated.
In the end though, nothing came of it and there's no evidence of any kind that Snowden has ever edited Wikipedia.
But it's hard to see how any of this would be relevant to anyone. Even Snowden did edit the site, what would it tell us? He wouldn't have been able to disclose anything that wasn't documented elsewhere, as per Wikipedia policy. At most, we'd know what articles he edited, which doesn't really mean anything.