The risky moment will come when Beijing loses faith the trend of history is still pointing towards growing Chinese power and declining American influence. As long as the Party leaders still feel time is on their side, their marxist belief in the determining power of underlying structural material forces will give them the reassurance they need to prioritise stability and development.
As for domestic Taiwanese politics, One Country Two Systems never had much draw on the regular people. Much of the enthusiasm for closer integration with China in Taiwan is limited to a Deep Blue elite that has no particularly strong commitment to either Taiwan or democracy. But they never had strong mass support for such risky moves.
What Hong Kong has done is not so much change the natural trend of consolidation of Taiwanese identity with the passing of time, as make it much more uncomfortable for KMT leaders to still advocate appeasing Beijing.
The consequences of the developments in Taiwan strengthen deterrence and increase risk. On the one hand, greater agreement in society about Taiwan's de facto independence unifies society and helps politicians work on strengthening the military defence.
On the other hand, it might in time also convince people in China about the unviability of continuing maoist rhetoric about the people of Taiwan being misled by an 'extremely small minority' of Taiwanese independence extremists and the ‘foreign forces’ backing them. Already a while ago China Taiwan Net—the news site of the PRC’s Taiwan Affairs Office—had a commentary summarising a China Times editorial worrying about the DPP’s supposed anti-China programme and desinfication efforts leading to growing negative sentiments towards China in Taiwan.
But even then we still have the military calculation and Beijing’s trust that time is on its side with regards to the material balance of power still.