GSP was never knocked out cold and neither was Wanderlei before his career went anywhere (he was TKOd by Belfort, but was not out cold like Niklas was; take a look at his career trajectory after he did go out cold, though).
In addition, I said "traditionally" and you appear to have demonstrated my point. Out of all of the fighters in recorded history that were knocked out cold in a contest, you are only able to name two that had somewhat of a decent career thereafter.
Pro-tip, be cognizant of the argument being made before attempting to deconstruct it. On another note, it is hardly "impossible" to establish such a trend. For example, one could note a fighter's respective trajectory and fighting capacity, and if that fighter experiences an "out-cold-event" you could then monitor their activities thereafter and make further predictions and analyses.
Renan Barao was knocked out cold vs Claudemir Souza, Cain by JDS, Mark Hunt by Manhofe and JDS, Bensson Henderson was KO'd as an amature, Machida fought for two titels after the second Shogun fight, Mirco by Randelaman, Shinya Aoki has been out numuerous times and still has one of the best resumes at lightweight...i think its safe to say that theres more than a "few" fighters who have gone one to have a stellar career after being put to sleep.