Why doesn’t GW tell us what’s on the sprue?

As im building out this new Ork army, im running into the age old problem on not know what box sets I really want to buy. I picked up a new box of Ork Nobz, to find a number of excellent weapons on the sprue! Excellent! I was expecting this and would have been disappointed had they not been there, however I had to way of telling prior to opening the box. Is there any easy way to find out exactly what comes in a box my GW comrades?

Anyone interested in seeing all the sprues I purchase so you too can know what comes in a box?