I think it’s utterly vital that controversial views are aired, and that ludicrous fascist and racist views are publicly exposed to ridicule. But student unions are private organisations, governed generally democratically, and they must equally be free to decide on what policy they will take towards external speakers. The “no platform” policy of the NUS which is mentioned in the article is very narrow – it applies to six specified organisations, and forbids the use of union premises, speaking at union events, and rules out membership of those organisations for union officers.
Personally I don’t think it’s worth the cost, in particular because these policies have muddied the debate with a lot of ill-informed misinformation from every perspective - the various controversial speakers, for example, are not subject to any “no-platform” policy, but have been excluded from discussion based on the decisions of individual students.
Frankly the far bigger problem is the attitude of those individual students. It’s been about a decade since I was at university, but even then the entire sphere of student politics was filled with ill-informed reactionaries who had very little tolerance for the idea that people might disagree with them while not being evil. The idea of Peter Tatchell being excluded from a discussion of gay rights is outright ludicrous, and just reflects the bubble that these folk tend to live in.
That’s the thing we should be worried about, rather than some bogus hand-waving about safe-space policies that don’t actually exist and are just red meat to the usual shit-stirrers.