My experience with TW games is that it takes about 30-40 hours to determine if the game is good, i.e. play through to mid-late or late game and learn the systems, AI behavior, etc. It's comparable to Civ or EU, CK in this regard. Keeping that in mind, it's unlikely we'll get quality feedback or feedback we can trust during the first week -- unless the game is an outright bomb and that's unlikely. We could get professional or amateur feedback that is wrong, whether it's positive or negative, from someone's first 20 hours of play.
So let's be honest here. Extending the pre-order deal into the first week after release is nothing more than showmanship. If you're going to pre-order or become early adopter of TW:WH for the pre-order bonus, it's because you love WH fantasy so much you can't stand waiting. I get that, but let's not be disingenuous about why folks are pre-ordering or buying at release. Drillmaster for example is being honest about it below.
Now fans have another good reason to wait, Nvidia is releasing its GTX 1080 at the end of May and its GTX 1070 in mid-June. Who would want to spoil their DX12, 64 bit playthrough on an inferior card....