They claimed to have, but they failed. They did manage to create a 7 block reorganization, but since that's less than a 10 block lock, it's still a failure.
They either need to put up, or shut up.
Discussion
We’ll see how long #Qubic can keep their attack running. Ultimately, the public attention will wane off if they can’t do better. Still, it’s not great that they can create so much disruption but so far the #Monero network has shown its resiliency.
Even within the thread shared above many tangents appear. If indeed qubic successfully 51℅ what would we logically see happen to verify this? What are qubics goals in doing so?
If they did achieve over 51% for an extended period of time, they could, and likely would, orphan blocks from other pools, making their pools the only one that could get any blocks, and therefore making themselves the only ones who could mine. And if you weren't using their pool, you would not get any mining rewards at all.
As for their goals, who knows. They could just be doing it to prove that it can be done. They could be doing it to get attention, or they could be a state actor. Doing it to try to kill Monero.