I hope all of them will be coming back, and very soon, to their native countries.
I think they will. Why? Because in the eighties when Ireland's economy tanked, people left in droves.
Then the government cooperated with businesses to enact policy changes that encouraged economic development. (I think many countries could take a leaf from that book, even mine). Now with Ireland's economy turn-around, people who left years ago are returning home. It won't be the same as when they left, but now there is a reason to work and live there.
I think Poland is very much poised to do the same. I think the country has to go through a "shake up" to get where it needs to be (you have to tear down an old house to build a new one in the same spot, so to speak). I have some concerns about the government's role in this process, because the current leaders are conservative, and a lot of change needs to happen in order to make room for a new nation. It is happening, but I think it needs some speed to keep people happy.
So don't worry, they will come back home.