Verbatim republication of a journal article as a book chapter, with no acknowledgment of the article. Common practice or misconduct?

Hoping someone can tell me whether I'm reading this right or making too much of it.

A scholar publishes a peer-reviewed journal article in 2020. The next year, the same scholar publishes a single-author book with a major academic press, and one chapter of that book reproduces the article almost verbatim. Same paragraphs, same footnotes, same archival document numbers, even small typos that carry across. Sentence-level overlap is over 80%.

The 2020 article is open access under a CC BY-NC-ND license, with copyright held by the publishing academy. The 2021 book is "all rights reserved" with a commercial academic press. The book's bibliography includes several of the author's other works but doesn't cite or acknowledge the 2020 article anywhere. No preface note, no chapter-opening footnote, nothing in the bibliography.

I know this isn't plagiarism in the traditional sense since it's the same author. But I have some questions for people who've thought harder about this than I have.

1. Is undisclosed self-republication (text recycling, duplicate publication, whatever the term) generally accepted, generally considered misconduct, or does it really depend on the field?
2. Does the change in copyright holder (academy to commercial press) raise a separate copyright issue on top of the ethics question, or does the journal's standard author reuse policy usually cover that?
3. If the usual fix is a footnote saying something like "an earlier version of this chapter appeared as," does the complete absence of any such acknowledgment change how this should be evaluated, or is it just a housekeeping miss?
4. Do norms differ for academic books aimed at general or trade readers versus peer-reviewed monographs?

Field is humanities, area studies. Happy to share more detail if it helps.