There's truth there but this line is over-used. Playing chess better than a human was never deemed impossible and the ultimate solution doesn't seem to have any crazy insights that would stun a researcher from the 1960s. (You can read the source for Stockfish which is state of the art and open source). The improvements came in the form of more and more horsepower through hardware, more and more efficient innovations in the tree search very specific to the game of chess (bit board representation, move ordering), and simplifying evaluation and tweaking parameters according to unsupervised learning. Correct me if I'm wrong?
At the end of the day, chess (and go) are discrete games with perfect information played one turn at a time according to a tree of simple and trivially determined possible moves with clear criteria for winning. I don't see why we'd put this on a pedestal as the example of something generally considered uniquely human, so we'd better expand our imaginations of what we can achieve with AI. As the parent said, the mistake may have been in supposing there wasn't a solvable evaluation function for Go positions when in fact, through some more human ingenuity, there is.