I think if you change War of the World enough, it stops resembling anything people associate with War of the Worlds, apart from the alien invasion story. So that raises the question if it should still be called War of the Worlds if it is that different. On the other hand, there's only so many times you can remake the same story before it starts to feel completely redundant. A remake is only as good as how different it is from what came before.
For example, John Carpenters' 'The Thing' is a lot more accurate to the book it is based on ('Who goes there') than 'The Thing from Another World', on top of having spectacular practical effects and being updated for a modern audience. Likewise, although Kubrick's 'The Shining' was a fantastic film, it is a well known fact that author Stephen King wasn't a fan of it. So there is some added value in a remake that respects the book more (although this does not guarantee a better movie of course). If you're going to do a remake, I think it should be notable different in some important way to validate its existence.
War of the Worlds is a rare case of a story that has been translated to so many different mediums, most of which deviate a lot from the original story. Jeff Wayne's album is one of the few adaptions that actually included the vessel Thunderchild, for example.