it seems contradictory in the least, how old is that last part? cause it sounds like before Ghazghkull started his galaxy wide Waaaaaagh. back during the last Chaos crusade. (or are they on a new one now?)
No given date I've ever seen for the start of Ghaz's Waagh.
Basically its saying, the more the Gods in the Warp fight, G&M fight harder/back.
No winner. Just fluff ideas to fire the brain.
I woidnt count any of it as hard cannon given 2nd ed fluff to now.