I choose to believe it.
Severe dehydration has lead to a brain damage.
I'm a bit puzzled on why he wasn't wearing a mouthguard (as teeth marks suggest).
Sounds like a decent match up as both are on similar level right now and both lost 4 times in their last 5 fights, so are desperate for a win.
I'm not very familiar with Silva, but judging by his record he's pretty aggressive with 20 out of the 23 wins by KO. I don't think it'll be a walk in the park for Weidman, but good to see the UFC still gives him fights and didn't dropped him after that horrible injury.