This exemplifies my point perfectly. Even though you go on to write that some were born in the country, they are still "Turkish immigrants" not "expats" or [that country's] citizens. Some may be considered expats by you now but walking down the street I can assure you people see "immigrants".
Say "British immigrants", or "US immigrants", or "German immigrants" and see how that rolls off the tongue. Now say "Polish immigrants", or "African immigrants", or "Mexican immigrants".
English has this distinct connotation for the word "immigrant" and it's associated with individuals overwhelmingly based on their country of origin (the poorer the country, the more "immigranty" the person).
I am a white male coming from a reasonably developed and civilized second world country (literal and figurative definitions apply) to follow a high end job. Yet the second I open my mouth I am very much an "immigrant" in the eyes of most locals.
I was born in Australia, my mother was born in Scotland. In my mind, that makes me a second generation immigrant. I never thought of my mother, or her parents, as "expatriates".
A lot of Australians who immigrated from the UK and Ireland identified themselves as "immigrants" not "expatriates".
Yes, they're definitely not expats by the definition I gave earlier - those who move for work. Considering second+ generation residents as immigrants was really a mis-edit on my part, though they are seen by "natives" here as immigrants, often.
But you're kinda focussing on a point I wasn't making - that (in my experience, where I am), it's not only white people who self-identify as expats. Russians, Bangladeshis, Kenyans, USians, etc. are all generally expats if they moved for work.
But in rich countries that are old enough to have a population that already forgot they probably also came from elsewhere (populations have always moved around, replacing, killing, and/or mixing with the locals), recent waves of immigration are always from poor countries with a very different culture/language (so that they have trouble assimilating, getting jobs, contributing and so on... and many end up giving up and start to feel marginalized, causing some to appeal to crime) which made the word immigrant have a very negative connotation... hence the need for people from other rich countries to distinguish themselves from those poor people and call themselves something more respectable like "expats".