It is a safe bet. As the secretary of security during the riot, John Lee has demonstrated his loyalty to the central government. However, Donanld Tsang, Carrie Lam or John Lee were all from the colonial era and trained by the British so they have had strong tie with the UK government. Although HKPF was probably the only branch within the HK government that pledged their loyalty to the central government very early on.
I would say the next candidate for HK Chief after John Lee would also come from the HKPF. It is a way that the central government rewarded the HKPF for being loyal during the riot. It is also a message to HK power brokers that HK security, loyalty, and the will to enact reforms would be the most important things in the next few years.
