I mean, if I understand it right, now Riven can get a 10% boost in all damage? So her burst from her abilities are even stronger.
This reminds me, I actually haven't tried Riven at all since my ping was lowered from 120 to 45.
10% is if you have full stacks of edge which is not good if it only stacks on champions. Second this severely nerfs her Wind Slash since the damage is gated by how much stacks you have. Wind Slash is the most impactful ability Riven has in team fights. So this is basically a nerf to team fights.
All I see in these changes is that they don't want Riven to be an Assassin anymore and they want to turn her more into a bruiser. Stacking edge means you have to be in a prolonged fight and not small skirmishes. This means you have to buy some tanky items to survive in a prolonged fight.
Potentially, this could be a buff to her laning phase since the edge stays for 10 seconds. You could manage your cooldowns so that you can apply Q-autos and add more edge making you deal more damage overall. You can do that since you only need to be wary of a single person but come teamfights I don't expect Riven to have full stacks of edge at unless she builds a bit tanky.
I don't know why they did these changes. Most of the QQs about Riven is her laning phase and all I see is buff to her laning phase. So basically what this update does is to buff her already good laning phase and nerf her already bad team fights via nerfs to her Wind Slash.
Anyway, I don't know how the changes will affect her since I haven't played that version of her yet but from what I see I don't like it. If this will make her OP then I don't like it either. All that will result is Darius 2.0 where she will be 100% pick or ban.