You can't determine the meaning of a word or phrase just by interpreting its linguistic roots. Yes, Dark Souls is Japanese, and a Role Playing Game (I guess; I haven't played it), but the term "JRPG" doesn't merely mean "Japanese Role Playing Game". It refers to a particular style of game that, until quite recently, was exclusively made in Japan. This is what puts the "J" in "JRPG", but the term wasn't invented to split Japanese RPGs off from other RPGs just because they were Japanese (as the linked article suggests). There's really no reason to do that. If that's all it was, we'd just say "RPG". It was invented to describe a particular aesthetic that was very distinct relative to other CRPGs.

I can see the logic behind redefining the Legend of Zelda as a JRPG. That said, it would have been an invalid classification at the time, as there was a world of difference between something like Dragon Quest and something like The Legend of Zelda, and the entire point to the acronym "RPG" was to distinguish the two. Weirdly, we called LoZ an "adventure game", though there is no relationship between the term "adventure game" on the console scene, which described what we would now call an "Action RPG", and "adventure game" on the PC, which described what we would now call by names like "Object Hunt" and "Visual Novel". Words are weird, and their meanings can't be deduced simply by breaking apart their linguistic roots.