Thank you for your quick answer, @Nemo_bis. Parsing the html is of course always a last resort, but the API is so much better. I understand that fair use is not a license, but then maybe there could be a simple indicator of whether the image is free or fair use. Or maybe some extra parameter to the API that would include the fair use images in the response too. Any solution that would bring back the possibility to retrieve via the API the page image(s) even if they are fair use would be great!

I appreciate the care to licensing policies, but this change broke my project and probably many others. Why don't you leave third parties to decide for themselves in the licensing policy of each image is compatible with their use case? This would be much better than simply removing non-free images.