So if that Edge resource doesnt go to riven, can it go to a new champ/reworked champ?

It does sound like something that belongs on a new champion, not on Riven.

Its basically tryns passive just without rng, play tryn.

I like how whenever they try to destroy eve they put the changes up along with super a super popular champions change so they can try sneaking it though without anybody noticing, they tried it on that last nerf they had to pull from the pbe due to backlash as well.

TL:DR Riven will be fine these experimental changes are just to hide the eve nerfs on the pbe.

What's an "Edge" resource?

Riven has been a highly versatile champion for some time, and doesn't really have to pay anything for it. By giving her a resource to manage she gets a little more balanced without completely changing her kit around. My bet is that skilled Riven mains (BoxBox I'm looking at you) will be able to deal more damage with a bit more effort put into it. It also provides clear counter play (like Renekton with a full meter) of when you can expect her to dive / melt you. I like it and how the idea pays off, but alas I don't have a PBE account.