As I understand it, in order for an international adoption to be finalized, there has to be a genuine established parent-child relationship. If children then receive citizenship, it is because they have a Canadian parent who is either in the first generation and meets the substantial connection requirement, or the parent is already a Canadian citizen who is able to pass on citizenship. If the parent then dies following the adoption, that does not sever the adoption. The adoption would stand. The child's citizenship would stand.
On May 29th, 2023. See this statement in context.