I don’t see how handing HK over to ROC would have been “pro-colonialist”.
Giving HK back to China is an act of decolonization. Putting them under Taiwan and loading up the island with US weapons would not be.
PRC is itself a colonialist power. See all the Uighurs in concentration camps.
I don't want to devalue your experience, but Anglo powers have a terrible record of "colonialism for their own good", "we'll be greeted as liberators", etc.