Yes, that section of the article is discussing historical POSIX prior to 1997. The next section discusses the forming of the Austin Group and from then on only

Yes, that section of the article is discussing historical POSIX prior to 1997. The next section discusses the forming of the Austin Group and from then on only talks about 1003.1. The only place that article uses the phrase "POSIX.2" is to refer to the historical 1003.2-1992 (that "1992" is a year, if that's not clear).