"Unusual Speed"? This is just another step. The world sat back and watched, years ago, as China replaced Hong Kong leadership with the express purpose of accelerating Hong Kong's absorption into China. Newspapers with opposition views have been shut down for years now.
I was in Hong Kong in the week leading up to the protests set off by the extradition bill. Cabbies were telling tales of people being disappeared, the new extradition law, and the great faith they had in Trump, given his anti-China rhetoric at the time.
I felt bad, sensing they had some fundamental misunderstanding of his character. A lot of people in the US did too, at the time, but these people were so much more desperate that it seemed even worse to give them false hope of support.
They day after I left, the protests broke out. I couldn't really do anything. So I watched thew news. They got very little help -- some visa support from Britain a year later was probably the most substantive.
And it turned out Trump truly was just a showman. The executive order that was spun to look like some kind of hard response was in actuality just a codified US rubber-stamp on China's goal of absorbing Hong Kong: it basically said Hong Kong was no longer sufficiently autonomous for the US to treat it any different from China, and removed preferential treatment as a result.
We're not going to see the same level of protest again, even now with stricter direct security laws. The people of Hong Kong have learned that the world won't support them, regardless of how vocally some figures make their rhetoric.