The article answers your question in the first paragraph, "... but just because you hear something is true doesn’t mean it is...". This is from the next paragraph, "...reusing MLS head gaskets and the success of the practice, its failure rate is much higher after reuse...". Here is the next paragraph, "...Now, if you’re in a total bind at the track and need to reuse a gasket for only a handful of runs it’s not ideal, but it can be done. If you’re trying to reuse a head gasket as a long-term solution, that’s opening a dangerous door to many problems. The risks involved with not using a fresh MLS head gasket far outweigh the benefits enough to make it a good idea to keep a spare set on hand at all times...".
They are basically saying that it is NOT a good practice, and it is certainly not advisable once the engine has run, but in a pinch, you might get away with it at the track. So, with all of this maybe and probably, I still refuse to risk a customers engine and my reputation to maybe's. I will always err on the side of caution, and suggest to not reuse a Cometic gasket.