Darío Fernández-Morera, the writer of the article you linked to, has also written this book. I haven't read it but I posted a link to a review of it on the random Islamic history thread (however see also the comments by Zaotar and Zimriel a couple of posts below):
https://www.councilofexmuslims.com/index.php?topic=28609.msg867365#msg867365 The other comments and reviews of the book that I've seen have been critical and I don't think it's because everyone subscribes to the idea of al-Andalus as an example of tolerance and multi-culturalism. For the history of Islamic Spain more generally the Ballandalus blog is pretty good:
https://ballandalus.wordpress.comEdit: The original link to the review is broken - try here instead:
https://wp.nyu.edu/sjpearce/2017/03/17/paradise-lost/The article linked to in the OP is on a site promoting conservative ideas. Obviously content on the site has to be judged in its own right but it's maybe worth bearing mind where it's coming from politically. Here's some background on the Intercollegiate Studies Institute from a sympathetic source:
http://humanevents.com/2004/02/10/intercollegiate-studies-institute-turns-fifty/ and an article that puts Darío Fernández-Morera at number three on a list of the 'top ten contemporary academics helping the political right':
http://www.poletical.com/academics-helping-the-right.php