JR Pass in Japan

Are JR Passes available in Japan through March 2019? Japan-guide.com says they are but the official website says otherwise.
Japan-guide:
'"From March 8, 2017 until March 31, 2019 (and possibly beyond that date), it is also possible to purchase the Japan Rail Pass at an increased cost (see table below) at selected stations inside Japan. The stations include Narita Airport, Haneda Airport, Kansai Airport, Shin-Chitose Airport, Tokyo, Shinjuku, Nagoya, Osaka, Sapporo, Sendai, Niigata, Yokohama, Hiroshima, Takamatsu and Hakata. Purchase will become possible at several additional stations and airports from March 20, 2018."

Japanrailpass.net:

" JAPAN RAIL PASS is being sold at certain sales offices in Japan from March 8, 2017 to March 31, 2018.
※ Restricted to individuals who possess only a passport issued by a country other than Japan
(purchases cannot be made by Japanese nationals living overseas)."

japan-guide.com is more up-to-date that the pass' English official website.

It was announced a few days ago that the period of selling the pass inside Japan will be extended by another year:
https://www.jreast.co.jp/press/2017/20180215.pdf

Personally, I suspect that the pass will eventually be permanently sold inside Japan (or the pass gets revamped otherwise).

It's cheaper to buy it outside of Japan.

If you must check, check the official web site and not reseller, this site is probably more accurate that what you have links, as it's usually updated regularly.