You quote a section about unpublished work. The painting was published nearly a hundred years ago so the quote isn't relevant. If you think the article is wrong please state how.

I don’t see that. “For works published or registered before 1978, the maximum copyright duration is 95 years from the date of publication, if copyright was renewed during the 28th year following publication” may not apply here, but if so, it isn’t because the work was published.