It is in favor of EU member states cutting aid to refugees as a means of exerting pressure

Not going to happen in Germany, welfare is (perpetually) at the constitutional minimum. Kicking people out OTOH is an option, especially for people without job or kids. Kicking kids out won't happen before the end of the war and without job, depends on the employment market. Depending on how quickly Ukraine joins the EU, possibly never.

What's going to be an issue is the draft: Ukraine is likely to have to guarantee that noone is going to be forced to serve at arms they'll have to offer positions in the rear, civil defence, etc... which is then going to cause a discussion within Ukraine whether that shouldn't apply to everyone, not just people who were in Germany.