Like already stated, saying that Alpha Zero has forced the chess world to seriously reconsider the basic principles of chess openings etc. is a bit of a stretch. But interestingly enough, the current world champion (Magnus Carlsen) is having the chess streak of his life as we speak. On the side, he's been openly joking about Alpha Zero being one of his biggest chess idols. It's safe to say the streak is probably mostly related to his preparation from the last world championship match half a year ago carrying over to all the tournaments after.
However, even according to the former world champion (Viswanathan Anand) the run he's been on is something quite shocking: “His results this year is simply [great].... difficult to find words. [It’s been] completely off the charts. I think the chess world is still in a bit of a shock. The rest of the players are struggling to deal with a phenomenon [like him]. Even in 2012-13, his domination was less than it is this year. Everyone is still processing this information.” [1]
Carlsen is basically on route to breaking 2900 Elo - at 2882 Elo with a clear upwards trend - while there's only two other active players even above 2800 Elo and struggling to keep it above that treshold. (Elo is the rating system used in chess. Above 1500 Elo is an average player, 2000 Elo is a good player, 2500 Elo is a grandmaster. Anything above 2700 Elo is basically godlike.)
Oddly enough, instead of playing more like a machine, it seems like Carlsen has been playing chess that is much more about the human aspect of the game rather than trying to find the top ranked engine move on every turn. (The current traditional top engine - Stockfish - makes an assumption of each move's validity using a point system, which the chess world has been more or less obsessing over for the past decade. Alpha Zero doesn't have such a point system whatsoever.) He's been playing a drastically more aggressive and dynamic variety of chess compared to what has been seen in a long time at the top tournaments.
He's been playing to create dizzying positions on the board, making a few moves that aren't necessarily liked by the traditional top engines, but still finding himself in a winning position several moves after. It definitely looks like some sort of black magic, but it seems like the big thing Alpha Zero has brought to the general philosophy on how to approach chess at the top level is that it's possible to play aggressive chess, take risks and win in 2019. Magnus Carlsen is the first player to successfully reinvent that style of play, more than likely partly inspired by Alpha Zero. So, I'd say the big thing about Alpha Zero isn't necessarily that it could beat the other top engines, but more importantly that the 'artistic' aspect of its play is something that has never been seen from another chess engine. The fact that it proved that sort of style superior to the play ever before played by another chess engine is just the icing on the cake.
Garry Kasparov on Alpha Zero's chess persona: "I admit that I was pleased to see that AlphaZero had a dynamic, open style like my own. The conventional wisdom was that machines would approach perfection with endless dry maneuvering, usually leading to drawn games. But in my observation, AlphaZero prioritizes piece activity over material, preferring positions that to my eye looked risky and aggressive." [2]
However, even according to the former world champion (Viswanathan Anand) the run he's been on is something quite shocking: “His results this year is simply [great].... difficult to find words. [It’s been] completely off the charts. I think the chess world is still in a bit of a shock. The rest of the players are struggling to deal with a phenomenon [like him]. Even in 2012-13, his domination was less than it is this year. Everyone is still processing this information.” [1]
Carlsen is basically on route to breaking 2900 Elo - at 2882 Elo with a clear upwards trend - while there's only two other active players even above 2800 Elo and struggling to keep it above that treshold. (Elo is the rating system used in chess. Above 1500 Elo is an average player, 2000 Elo is a good player, 2500 Elo is a grandmaster. Anything above 2700 Elo is basically godlike.)
Oddly enough, instead of playing more like a machine, it seems like Carlsen has been playing chess that is much more about the human aspect of the game rather than trying to find the top ranked engine move on every turn. (The current traditional top engine - Stockfish - makes an assumption of each move's validity using a point system, which the chess world has been more or less obsessing over for the past decade. Alpha Zero doesn't have such a point system whatsoever.) He's been playing a drastically more aggressive and dynamic variety of chess compared to what has been seen in a long time at the top tournaments.
He's been playing to create dizzying positions on the board, making a few moves that aren't necessarily liked by the traditional top engines, but still finding himself in a winning position several moves after. It definitely looks like some sort of black magic, but it seems like the big thing Alpha Zero has brought to the general philosophy on how to approach chess at the top level is that it's possible to play aggressive chess, take risks and win in 2019. Magnus Carlsen is the first player to successfully reinvent that style of play, more than likely partly inspired by Alpha Zero. So, I'd say the big thing about Alpha Zero isn't necessarily that it could beat the other top engines, but more importantly that the 'artistic' aspect of its play is something that has never been seen from another chess engine. The fact that it proved that sort of style superior to the play ever before played by another chess engine is just the icing on the cake.
Garry Kasparov on Alpha Zero's chess persona: "I admit that I was pleased to see that AlphaZero had a dynamic, open style like my own. The conventional wisdom was that machines would approach perfection with endless dry maneuvering, usually leading to drawn games. But in my observation, AlphaZero prioritizes piece activity over material, preferring positions that to my eye looked risky and aggressive." [2]
[1] https://sportstar.thehindu.com/chess/viswanathan-anand-on-ma... [2] https://science.sciencemag.org/content/362/6419/1087