There is no total control. That’s a direct link between a producer and a consumer. Nobody cuts others from the existing infrastructure. The intermediaries are losing their transit monopoly though.
And above all Poland and Baltic states has LNG terminals to get gas by sea from anywhere they wish, US included. Ukraine might get its gas from Poland as well.
Nobody gets frozen even if Russia and Germany want it although the idea is laughable.
With all due respect, you contradicted yourself. The intermediate countries are themselves customers and not merely transit hosts.
Russia’s already cut off the gas to former eastern bloc countries; the side effect was that Germany got cut off too, but NS2 prevents that now.
And of course, the raging TDS among Germany’s leadership is accelerating the desire for a gas link like this.