Thanks. It appears that I was incorrect about by who originated it. I thought it was by the National Union of Students in the UK, but it was not. It appears to be created by some Trotskyist group called the International Marxist Group. It seems it originated as, uh, perhaps a reaction to a literal fascist group in the UK known as the National Front. I understand the goal of it is to try to limit the propagation of fascists and/or racists ideas from spreading further.
This "no platform" stuff seems very easy to manipulate in one's favor and/or used to attempt to silence ideas that are deemed controversial or ideas/ideologies one disagrees with. Instead of it being for certain literal fascist groups, it can be broaden to include any group, regardless if they're a fascist group or not. Like it imposes this wide policy upon the individual or group that had no say in said policy or to enact it and that seems to me to be incompatible with my understanding of anarchism.
So, like recently, some book publisher (the one in your link) published a book that's controversial to some. Because it's controversial, the publisher is "platforming" according to the established anarchist policy that I've never heard of.
The article you linked here, I suppose, indicates how the "no platform" thing can easily be broadened and manipulated to fit in more groups than the initial intent of "no platforming." That article was kind of silly and full of buzz words that. As far as I can tell, it seems it's possibly over ideological differences, not the book itself, but it could be the book also. Maybe the book is just a convenient scapegoat. I guess, I kind of answered my own question and you answered the first part. :) Wonder what others opinions are about the "no platform" stuff?
Technically, wouldn't the guy that wrote that article and other folk complaining about it, be the ones that are "platforming?" I don't believe many people would have knew about the book if it wasn't for the constant complaining over of it. The folk complaining about this book are the ones propagating the book itself and the ideas in it that they've may or may not read. At least that's how it seems to me. If it's to prevent the propagation of the book's ideas, they're going the wrong way about it, imo. It's like the Streisand effect