It doesn't get much more elementary than "Those who forget history are doomed to repeat it."
Of course this revision is short sighted. It makes the current generation feel a little better by turning it's back on some nasty memories, but hoses over the future generations.
The lesson's already been paid for in blood, why throw away the only value created by discarding the lesson?
One asks? Who authorized this? And why? What is their motivitation? What is next on their list?
This Abe chap is sure urinating all over his friends (or at least friends he should keep): various nations around Asia over Yasukuni and very recently (denial of) the Sex Slaves conscripted into the war to service Japanese soldiers, and now this, over Okinawa--deleting references to the hand the Imperial Army had in it, insulting the Americans.
Next thing you know, they will take out any references to the attack at all on Pearl Harbor, or perhaps surmise that we did it to ourselves as pretext to go to war against the Empire. I wouldn't put it past this current crop of buzzards. This is worse than the movie "JFK" for pete's sake.
The same can be said for American history.