The Rinfu is a truly fabulous rod, although my impression was that it had been discontinued. I bought one 3.5m and one 4.5m to evaluate but when I decided do import them I was told they were no longer available from Daiwa (may have been a misunderstanding - I took it to mean discontinued but it is possible they were just sold out. I will try to clarify that. If they will be available in the spring I will definitely have them in stock!) As near as I can tell, "rinfu" doesn't have an easy translation into English, coming out something like "cold breeze that makes you sit up and take notice." I would not have categorized the Rinfu or Sagiri as keiryu rods but as seiryu rods, or hae rods. In this usage, hae does not mean fly and they are not called fly rods. That is a google mistranslation. Hae is the type of fish, so they are rods for catching that type of fish (called pale chub in English). (The confusion over hae=fish and hae=fly is very similar to the English bow=prow of a ship, bow=knotted ribbon in a girl's hair, bow=weapon used with arrows, bow=bending over at the waist.) Also, seiryu rods and tenkara rods are subsets of keiryu, so the Rinfu would have been listed under the category of keiryu (stream fishing) as opposed to ocean fishing, carp fishing, etc.
My personal reaction to the blog post was wondering what the big deal was. People here in the US who have been fishing the Madison in MT, Arkansas in CO, the Green in UT or any larger rivers have been using those techniques naturally for as long as they've had rods available. I think that is the difference between believing that you must look to Japan for all knowledge about tenkara on the one hand (with the admonition that if the masters don't do it, it somehow isn't proper tenkara), and just taking the rods and going fishing, learning as you go on the other. When the first learns that the masters in fact do it that way it is a revelation. When the latter learns they do it that way, it is "yeah, I thought so."