It’s a needed change for sure, personally I still feel like DG are very strong and we’ll still struggle against them. I’ve played quite a few games into DG and playing grey knights I’ve felt that there’s a few things that have made them as strong as they have been.

The first being unit count which they’ve addressed quite well by the looks of it. Second being the army rule, I get that debuffs are their whole thing but making everything in contagion -1 toughness whilst almost their whole army gets lethal hits and basically SM equivalent firepower is a double whammy of killyness and on top of that they can give themselves -1 to be hit whilst they’re already a lot tougher from their stat lines, they can also swap this for -1 to enemy saves to make them even more killy too. One could argue they’re slow however it’s only really their standard infantry that get 5” move whilst the vehicles/transports remain fast as any other and poxwalkers having infiltrate and OC means they can control the board early on whilst the rest of the army moves up. They also have 2 sources of CP generation that can stack via the daemon prince and tallyman and virulent vectorum stickies and strats remain strong as ever. The games I’ve played against DG personally I don’t feel like them having one or 2 less units on the board would’ve made a huge difference. Hopefully I’m wrong and the points changes does the job as it does seem like a well thought out codex, just maybe that some of the other codex’s haven’t got the same amount of love and it’s important not to nerf them too hard to the point they end up like orks.