In sports that are dominated by a single country or a very small number of countries I am actually very okay with seeing those questionable nationality change, and honestly if Canadian curling pros start getting poached by other countries it would make international competitions more interesting. The Qatari and Bahraini long distance runners do add to the spectacle, even if their presence feels a little artificial.
Ahn, IMO, was pretty justified in changing nationality. His national federation didn’t want him anymore, so in his mind it was clearly a choice between going elsewhere or retiring.
Both the men’s and women’s number 1 Canadian table tennis players were born in China, too (Mo Zhang and Eugene Wang).