So i take it they have been mining with this for the last few months and finally now decide to release it to the public, when mining is hardly profitable for GPUs.
They probably reached the point where they will make more profit selling these machines in April then mining with them directly themselves. And people will always get suckered in one way or another.
You are right. They use it at first for themselves. It is a real killer of GPU mining with 4-5 times better energy efficiency. It will definitely accelerate the transition to PoS of Ethereum.