This question can also be replied based on generalization in current context of Vietnamese society, I would rather classify Saigonese as, those who r not limited to the people who came from Saigon during the era of revolution, but also including those who flew from the southern territory of Vietnam after unification, such as the boat people, the reason I call them Saigonese simply because they mostly associate themselves with a tag of Saigon, like if they open an restaurant, the city name of Vietnam that they associates to, must be saigon, it won’t be Da Nang for example. Members of this classification sees Vietnam as a sort of homeland, but their connection to the Vietnamese is very weak, either because they are too old to updates their information about the nowadays Vietnam, or their descendant are unable to link their life to current Vietnam, these second to third generation of foreigners who are either children or grand children to a Saigonese, Vietnam to them is a very vague ideal, it is far from their life, what they imagines about Vietnam based on story telling, and the decoration of a restaurant, or of a supermarket, it is very much artist, to get a sense of it, I think the lyrics of “hello Vietnam” is helpful, and most local Vietnamese are aware of them, having them being the case like such, local Vietnamese either perceives them as someone who needs to return to their heritage of living , or to see them as foreigners only.
about the recent migrate to oversea, it depends on the place that they migrates to, for if they are living in the West, local Vietnamese tends to see them as people who has a relatively more comfortable life, can travels in between the Western home and Vietnam, like half year there, and half year here, very good; of course this is not easily doable, but this is how local Vietnamese perceives them. But then for those who migrates to places like Taiwan and China, and Korea , local Vietnamese only sees them as workers in oversea country, this is due to their assumption on the life of these oversea Vietnamese, but there’s truth to that assumption, like the Vietnamese brides, and then some man who are sent to these countries for construction labor works, though still rare, or to earn one money by opening a business, else be a cook in restaurant, the truth to these Vietnamese is, they don’t have a likely hope to be naturalized and settle there, so, eventually they will return home, but this is an assumption shared among them and the local Vietnamese, many of them do end up being either naturalized or obtain a PR in those places.
there’s one more group of youth, who are children and grand children of saigonese but decides to lives in Vietnam instead, they won’t be seen as either foreigners or Viet Kiu, they lives in Vietnam with the same routine shared by local Vietnamese, but their mindset surely distinguishes themselves from the locals, a mindset which keeps them as foreigners, or at least Viet Kiu, however, locals rarely cares to find out, they treats them equally without an assumption of cultural shock, although cultural shock is there.