@basedbagel
Yes, the current Germans would not be having enough kids either, but they can come and work right away as adults without any investment in terms of children being born and educated.
Just like all other cases of immigration, it solves the problem temporarily. Just long enough for the current politicians to be able to say "we fixed it" in the short term, they can retire wealthy while kicking the can down the road.
@basedbagel My guess would be that they would hope that Germany/Germans would not find out about this plan. Or if they did, they would still go along with it because they do not have better options.