Looking at a number of currencies performance extending back to the 2007/2008 global financial crisis, and focusing on the yuan in juxtaposition to the HKD, USD, GBP, EUR. Some interesting trends become evident, suggest that perhaps the PRC have a long-term strategy that they are working through in terms of Hong Kong's currency integration into the mainland's central planning, development and implementation, particularly with regards to large-scale infrastructure, Greater Bay Area projects, and the Belt and Road Initiative (BRI).
A relatively new factor is the civil unrest in Hong Kong; the PRC and the Central Bank of China have determined flexibility as to when they might perform the HKD anchor currency "swap out" date, which initially I would have predicted as being sometime towards the end of a second term US President Trump (granted that happens). However, depending on the direction, duration and severity of the Hong Kong protests, the Chinese Government has the ability to bring the date forward. If we continue to see the USDCNY exchange rate rise, a logical swap out date could be set once the exchange rate is around 7.5-7.6, providing a narrow range for arbitrage and thus similar to the current trading range stipulated for the HKD. This would effectively provide competitive range bound trading for HKD and CNY currencies, accommodating futures, long, and short positions moving forward.