The data suggests It's flat though and it accelerated too much to be a rock ... but there could be some error in how they computed that or some unknown phenomenon. I wish we had a way to just fly up to it or at least observe these interesting objects more closely, like maybe have hubble space telescopes spread out through the solar system ... would cost a lot but would be so nice to have more data!
The data on omahuomohua or however you spell is very lacking. I haven't heard anything about it being flat. But that doesn't really lead to one conclusion over another.
Considering this is the first interstellar object we've ever observed, there's no previous data to compare it to.
But basically if it wasn't of natural origin, why have we not detected anomalous infrared signatures? There would have to be some sort of heat produced from circuitry. Particularly if its goal was to study our star Sol.
Though the possibility exists. The likeliness of this interstellar object being an intelligently designed space craft akin to a von neumann probe is drastically out weighed by the probability that it's a chunk of rock that was gravitationally assisted and slung far out from a distant star.