> Now that it is well understood, moves of that type are common even in intermediate level play. Changed the game forever.

That's an important takeaway from the AlphaGo saga:

It played moves that (at the time, for human players) seemed weird. And while playing those, outperformed humans.

But as understanding of how/why of such moves grew, it showed humans new ways of doing things. And in doing so, become better players themselves.

AlphaGo broke new ground, humans followed. And like you said: changed the game forever.

Also, the subtlety of what makes a win:

Humans, before AlphaGo: try & grab as much territory as possible to beat your opponent.

AlphaGo: just try to grab more territory than opponent (so, not necessarily much more). End up with only 1 point advantage = still a win.

Different viewing angle, different strategy, different outcome.