Is what Germany is doing hypocritical: No. why should it be? germans don't break contracts.
Would Poland be a net contributor to the EU today if it's recovery hadn't been hampered by not getting reparations or help to rebuild post WW2:
nope. They could have opposed russian rule. they could have been in on the marshalplan. They didn't. Doesn't help if their working morale, corruption, and investment works like it did in the last 30 years. Just look up the numbers. Without germany building up infrastructure there would be even less.
Is Germany basically threatening to fine Poland for not taking as many of the Refugees Germany invited as Germany wants (despite having already taken hundreds of thousands of refugees over the past few years): no. The fine is for breaking a contract. You don't subscribe a contract and then break it. well maybe in the UK?
btw taking ukrainian refugees is a boon for poland, they actually get workforce instead of the rest of europe. but well, it sounds better to say refugees instead of imigrants
(which are about 1.3 mill and about 300k are war refugees... just saying)