Yes this new form of banishment / extrajudicial punishment has become popular in recent years -- it's pretty disgusting.Interestingly the UK has a provision that even if you were born in the UK, if considered a national security threat, you could lose citizenship.
I consider it a severe corruption of democratic norms. Something like "national security threat" is usually presented without evidence, in secret courts, without transparency. I think the western world has lost its mind in recent years over this terrorism paranoia.
I'll bet that China currently thinks that many normal citizens including university students in Hong Kong are "national security threats". It doesn't take much to become a national security threat... it's all in the eye of the beholder.
The UK and Canada were supposed to be better than these kinds of regimes. Thankfully, Trudeau stood up for democratic principles (and in fact he did it VERY quickly after taking office) but I am disappointed with the UK.