I don't want to say it's good news, but like you said, it's a best possible outcome. There's plenty of room for optimism in this. Having a MIL that passed from leukemia and my wife having a recent cancer scare, hearing this relatively good news actually brought a few tears to my eyes. My prayers are still with them but my spirit is lifted.Came back as ALL - best possible outcome for an awful situation. Hoping to go home next week and then looking at up to two years of 1x month chemo treatments. And that's apparently the "easier" treatment path. But still, thankful that it sounds like they have a plan that involves them mostly getting to be at home and a highly effective treatment plan.
This being said, I don't envy them going through chemo with a child for two years. Hopefully it will be less.