Yes, certainly this is correct as I have noticed that also. When people move money from their country out, the country loses that certain money and because it is done digitally there is little control of what and where will these money be used for. So it is like it is wasted if not used properly.
Do not forget the part where there could be inflow of money into the country as well. At least, if money is leaving somewhere, it is not just disappearing.
For instance, a lot of people have been doing well for themselves, some have been able to learn how to trade over the years, and make some pretty good returns on their trade, and looking at the fact that you will still need to convert to fiat to be able to spend at all at least for now, it makes it necessary to at least have a need for your currency which brings about demand for it.