The problem is still there, the drawing will probably suffer a significant downgrade and the story, even tho it will be "accurate", it will definetly fall quite a little bit.
The last like 5-10 chapters were barely drawn by Miura. And if you look at Duranki which is entirely by his assistants it frankly seemed to look better than Berserk did at the time they were both releasing
even if the art isn't as good, if the story gets to be finished exactly the way miura had planned then i'm okay with it, this brilliant manga deserves to be finished

berserk and HxH were the first manga i started reading nearly 20 years ago, for the past 10 years I had hoped i would get to see the ends but always doubted

this is great news

Garp the Fist

It’s the best thing we can possibly get.

Sure, it won’t be as good as if Miura did it. But Miura’s dead, and that just ain’t possible. This way we get the ending. There will be probably be some plotpoints that get dropped, it won’t be by Miura, but we’ll get the main story of Guts and Griffith wrapped up and I think we can’t ask for more than that.