An interesting tidbit (hinted at in the article) is that there’s an active effort to reuse old (no longer used) words for new meanings. An example is sími (telephone), an old word for cord/rope. I wonder how well GPT-4 copes with the issue of loanword vs coining new/reusing old terms.

Keep in mind that the similarity to old Norse was intentional. It was a form of linguistic nationalism to revert some of the dialect changes that had built up over the centuries during icelandic independence. They started teaching kids using the old books and used them to standardize the orthography. The vocal changes were a bit more sticky though.