It's just bullshit, Germany knows why those tanks can't be sent and is using it as a stall to prevent others from giving their German tanks. America supplied lots of Bradley and other fighting vehicles and many have TOW anti tank missiles and can kill tanks. M1s require extraordinary support and logistics are difficult to transport and many bridges can't support them. Uncle Sam needs to develop a lighter tank in addition to this behemoth, something that can be transported and allies can use, something to compete in the European market with leopards!
Poland and others might just say fuck you to Germany, give the tanks anyway and buy American or other Europeans for replacements. Joe could move M1s into eastern Poland near the border with Ukraine and start training crews for deployment west of the Dnieper river, for now. They would be in Ukraine, but in no danger of capture or seeing much action, but a reserve force. Also Joe could send even more Bradly's and other armor with TOWs.
This push ends the war in the spring and summer, this winter they will go with what they've got. It might not end the War when the Russians are driven out and then there is the question of Belarus becoming involved. If the Ukrainians drive south to the sea of Azov, it will force the Russians in the north and Belarus to attack, ready or not, as a diversion. I dunno how much of the Ukrainian equipment has been used up or destroyed, the Ukrainians big offensives in the north east and south were not very costly for them and they gained more armor than they lost both times!