I can understand not wanting to announce it prior due to market manipulation, however, you all have to understand how much plat was invested into these rivens. People grind for these, and it more of an endgame thing.
The changes don't really affect bad weapons. So they got a little buff? This won't necessarily cause people to use them. This did 'ruin' a lot of weapons for a lot of people. If anything make new rivens take on these properties, but don't make it a retroactive change. I feel so bad for the people who dropped 1k plat on a riven, only to have it nerfed.
I haven't read every post on this thread, but the majority I've seen all view this change as negative.