That's very interesting. Does it say any of that in 4e anywhere, or is it just your take on the subject as a 4e fan?
The only explicit reference is quite hidden--specifically, those things I said about Tiamat are (Scales of War spoilers)
canonically what happens if the players manage to actually kill Tiamat--not just an avatar or projection of her, Tiamat herself, in her domain, at the peak of her power. Greed and envy are naturally reduced in the world, because deities have a complex and intimate connection with/correspondence to the things they are deities of. The text is very explicit that this won't result in the disappearance of the things Tiamat was the god of, but it's still a pretty nice boost to the world overall.
There is, however, one actually "public"-facing aspect of this: the so-called "War of Winter" which came after, or in the final stages of, the Dawn War. Specifically, Khala, the god of Winter and Strength/Savagery, wished to plunge the mortal plane into eternal winter, which she (seemingly correctly) believed would make her the most powerful deity in all of reality--her domain would touch everything, and thus she would have power over everything. Zehir, Tiamat, Gruumsh, and (originally) Kord fought on her side, while Bahamut, Pelor, Moradin, and IIRC Sehanine and Corellon fought against her. The tide turned decisively against Khala when her son, Kord, was persuaded to switch sides because he saw that the fighting was hurting bystanders who had no means of defending themselves--he's kind of CG but in the "I only want to fight
worthy opponents" kind of way. Eventually, her faction was defeated (symbolically as well as literally--Bahamut besting Tiamat, Pelor besting Zehir, etc.),and Khala herself was struck down, stripped of her portfolio and banished into death eternal by the nascent Raven Queen, who demanded the Winter domain for her services. (TRQ is presented as a sort of "healthy ambitions" deity, since she obtained all of her domains by conquest or in exchange for services rendered.)
So, while I may be amplifying the message a bit and connecting in an obscure lore chunk that not all players will see, even the general text at least partially supports this reading.