Ehhhhh....I've got all sizes of 26" Minion DHF at home, multiple examples of each, and the old 2.35" is NOT the same as the new 2.30". Its much closer to what I said in my post above, where the new 2.30" measures between the old 2.35" and 2.5". The ETRTO width of the 2.35" is 52mm, but I'd say it looks a lot like a 2.2" by any classical reference.
Not only that, maxxis reps have publicly confirmed the sizing change several years ago. All new 26", 27.5", and 29" maxxis tires released in the last 3-4 years or so comply with the new sizing. You can even see the difference in the ETRTO's listed on the maxxis website.
http://www.maxxis.com/catalog/tire-468-121-minion-dhf
This is a thing. Hope everybody is fully confused now