CNA just came out with a series on them too. The parents of this particular family strikes me as a abit dim witted. And reason for moving not so much due to NSL or anything political but rather better housing lol.
The quality (actually the lack of it) of housing in Hong Kong is the root cause of a lot of social ills in the city. I remember visiting and staying with an expat friend in Hong Kong around the year 2000. His company paid US$3K for a ~300 sq ft apartment. His wife came and stayed with him for less than 6 months and moved back to their home country. She just could not handle the crowded space for their family of 3 and a maid.
Poor housing is one of the main causes for emigration long before the riot and NSL. The current Covid-19 surge is partly due to the kind of homes the majority of Hong Kong residents live in. An infected person under home isolation would infect everyone in the cramped household.
The government of Hong Kong is not able to solve the housing problem on its own. China needs to step in and force a solution to Hong Kong, like giving a near by island or area bordering Hong Kong for low cost housing.