Remarkable how long some lenses have been around.
A few errors unfortunately.
The original article is about the oldest lenses “available”, not “in production” as described on this site. These old lenses would have been produced in a batch, probably 10+ years ago, and sat in a warehouse since then. I doubt any of then are in production now.
The 200mm f2.8 II was introduced around 1996, not 1991. The 1991 introduction would have been the 200mm f2.8 which we now call the Mark 1 which hasn't been available since 1996.
The 50mm f2.5 macro is no longer officially available in my country. As it seems not to be particularly popular I suspect the B+H stock is a few leftovers.