I'd predict the opposite: that the Chinese dictators will crash their economy if necessary in order to not have to liberalize politics.
China is not North Korea. I don't think your scenario will happen, just like I don't think a Chinese collapse is plausible either.
First of all, China is not a dictatorship, but an oligarchy. President Xi has immense power, but he was selected by others in the CCP, and must balance other power players in the government.
Second, the CCP needs economic growth in order to sustain its legitimacy. No way it will purposely crash China's economy (how would they even do that?), because then the Chinese people will start to hate the party, and that's bad. That's why analysts have been freaking out about China's slowing growth, even though the economy is still growing at above 5% a year. Slow growth --> political instability.
That said, Frodo's scenario, while more plausible, is still up in the air. The government might liberalize, but on the other hand it might become more authoritarian and increase nationalistic fevor as another measure to shore up legitimacy.
Regardless, it's news like this, along with China's progress in many technology fields, that makes me optimistic about China's growth prospects. Other developing countries (e.g. Brazil) do not have such beneficial growth conditions as China's.