Well I saw koenma's other post asking about the cadet program so I assume she's in the same shoes I'm in, which is no flying experience. Assuming the likes of us get in via the CX cadet program, the only license we have is a HK one. This mean if a person decide to leave CX and join up with a Canadian airline, he or she would need to convert and I don't know if Transport Canada will let you do it stright convert with just a few exams. I have heard a taxi driver in Vancouver that use to be Iranian 747 captain.
Of course you can still bid for foreign basing when you get on the seniority list in CX and commuit if needed. From my research USA does not require Canadian citizens to get an Air Crew Visa. So you can live in Vancouver and be based in LA or New York, the commuit would be bad tho.