I suspect it has something to do with the level of pressure China can put on Canada, compared to how much Canada can fight back against that coercion.
As a result of the arrest of the Huawei founder's daughter - a much less direct challenge than to support HK protesters - we have had severe trade disruptions, 2 citizens, one of which an ex-diplomat, jailed on trumped up charges and another Canadian, a drug dealer, has had his sentence bumped up to the death penalty.
For our pains in acting on a US extradition request, we had President Trump shortly afterwards Twitter that the whole thing "could be fixed with a deal".
I suspect that, at this point, only a coordinated and concerted effort by Western countries to diplomatically punish China for its suppression of HK citizen rights would have much effect. And this is the kind of situation where recent US unilateralism and unpredictability makes that level of coordination less likely than usual.
So Canada's sitting this one out out of caution/timidity, yes. But I honestly doubt too many people are sympathetic to the CCP, even among more recent immigrants.