There are always expats leaving, and always new ones coming.
Since its not dirt cheap anymore, the bottom feeders of the mid 2000's are going somewhere else now- not sure where?
This is a constant flow, down towards the drain- Prague was big for a while, Berlin was cheap and empty in the 80's, Bali, or the beach towns in Thailand, Goa, the destination du jour for couch surfers and professional partiers changes every few months.
No big loss there.
But Argentina, and Buenos Aires in particular, has a lot of unique things to offer, and will always attract a certain number of new people from other countries. Arts, culture, music, architecture, literature, there is a lot here to attract some people. I think more film makers, DJ's, and artists have been showing up lately- the gallery scene, the music scene, the publishing scene are all still a lot more accessible and interesting than places like NYC, where the price of admission is so much higher, and the rents astronomical. It costs hundreds of thousands, at a minimum, to open a gallery in Manhattan these days. A pop up happens in BsAs weekly.