Writing a book expanding on a previous review paper?
I published my monograph in the field of chemistry in 2017, after I retired.

After writing a review paper on a specific topic, is it common to write a book to expand the review paper in a more pedagogical way, and to include more subtopics/content?

I have no idea. Others might speak to that.

Also, since published papers cannot be &quot;updated&quot;, would it be useful to have a book which takes into account new research directions and new results which have been published after the original review paper?

Other things equal, I would say sure! Anything that helps us assimilate the ever-rising flood of new information is welcome, in my opinion.

Would be writing such a book being a problem for copyright or other reasons?

In my experience, the answer is no. When I wrote my monograph, I requested copyright permission to use two of my papers as book chapters. It was easy, painless and fast: the publisher of the papers gratiously granted permission.
What else? I had always heard that writing a book was a labor of love. Now I really know that labor is the operative term and, regardless of the ultimate fate of my monograph, I know that I had it in me to persevere. So if you write the book, I wish you the best of success, and I truly hope indexing is not the largely unmitigated horror of the old days!