As I comment, the heavy sentences are disheartening but unsurprising given HK courts' national security first approach. The mere possibility the Alliance's activities might stir up hostility against the state—by reminding the public of past atrocities—is enough for offence to be classed as serious.
A Hong Kong court has sentenced three activists, who for years organized vigils in remembrance of China’s 1989 Tiananmen Square crackdown, to prison for terms ranging from 5 to over 7 years. The case has widely been seen as a barometer of the city’s freedoms.