New boxed game like Silver Tower, in another setting but fully compatible mechanic and game wise. In comparison to ST Shadows over Hammerhal dont's have brand new minis, only old ones, but all this is not that bad really. Here are three reasons why:
1 - fluff wise it's good as all the game fluff is linked together with Season of War, previous background and especially Tzeentch one in the book of his disciples. Also, although the heroes are all old, it's the first appearance of them in new universe, which is all we have now before they get their own books. So, we have here a duardin cogsmith, and that's great! It's not a Fyreslayer anymore, surprisingly, and although in the game it's a so-called named character without much general references, it's still great. Our engineer has helped with construction of the city defences and fights alongside other free peoples, which connects us with the fluff in the Order Grand Alliance book.
2 - model wise it's also not that bad as all the models are good and it's good to see them intact! And they maybe cheaper together for those who want them, especially with round bases. Also it can be useful for those needing only 10 kairic acolytes or blood reavers instead of 20.
3 - game wise GW further develop the role system element in the game and I personally always appreciate any such moves, especially for new players - for example, if you are starting your way into the AoS and like Chaos, this box gives you three full Chaos units and a hero to lead them - Chaos combined and good starting army! So we'll see what comes out of this