You are correct, Jroa. No collection of dishes in the desert can conclusively prove the shape of the Earth. Just as no photograph can prove the existence of a flat / round Earth.
Of greater importance is what it is officially reported to be. In this instance, it is reported to be a radio array collecting deep space and cosmological data. This is either true, or a lie. If it is a lie, then it must be something different; either a prop to mislead, or actually serving an unknown purpose. Generally, some deeper evidence beyond "It must be a lie, because it wouldn't work on a flat Earth, and the Earth is flat" or "We are told it is a radio array collecting data, so it must be," would be appreciated.
At best, we can speculate either side of the fence as to its purpose - there is interest in that, however, so continue on!