Older CC in tubes have not only the cedar sleeve but a small piece of cork in the cap. I have a few from the 70s that are just fine in the tubes, in beautiful condition and humidity, it's worked for 40 years, I'm leaving them exactly how I have received them.
No so sure I would use that article as the end all be all, there are a few contradictions in it and I don't know too many people that would leave the sticks, and we are talking some very valuable collections, in 70/70 conditions, or even their every day smokes, if I had to pull an average I would say 65/65 and a few myself included prefer around 62%.