They have probably gone silent because of the community reaction on the boards.
Right now it seems like a witch hunt rather than a "let's fix Rengar" thing at the current moment in time. People want the old kit instead of trying to find a compromise between his new kit and hit old kit.
In other words... if you want them to respond, you'll either have to give it time, or figure out a way to calm the community down a bit. It's like taking a lollipop from a baby, they'll cry for a while then calm down when they get tired.
If you want them to listen to a Rengar rework, then please, consider the following:
His Q, if possible, should not be an auto attack enhancer. This is too reliable on a champion with an ult that lets them leap on their target from further than a ranged basic attack can handle, as well as just being able to do this from bushes.
His old Q was too hard to balance. It gave too little room for his enemies to fight and too much for the Rengar. If possible, it should not be returned, because of these reasons. It probably tied down Rengar's power budget a little too much as a result.
His new Q, however, suffers from other problems. It solved the whole "no counter for opponents" thing because he had to already be next to his foes, but it feels... off, all around, from what I'm hearing. Clunky and just not fitting with Rengar himself.
So in other words, you need to think of a Q that is not only smooth and easy to use, but also something an enemy can play around besides "stay X units away from Rengar or pain ensues."
His W... I don't know the direction it should go, whether proactive or reactive. Both seem to have their own issues, so that is probably for those more qualified than me to say.
His E is stated to be fine, so we can leave that. No need to fix something that doesn't need fixing.
And finally, his Ult. His R. The infamous "I'm going to kill you and there is almost nothing you can do to stop me" ability. Time and time again, this ult has proved to be far too problematic. So what I suggest is simple; change it entirely.
It's clear that the ult, regardless of what it gives, will be a problem just because of the nature of how it works. If Rengar is ahead, you can't stop him unless you are a one main CC chaining master. If he's behind, it does nothing to help him. So why not make it more interesting instead of "stealth and see everything"? Make it so that Rengar has to interact with his surroundings. Like Rengar can leap from bush to bush around the map (not globally of course), or make it so that Rengar can track his foes. Simply revealing and giving an indicator doesn't seem to be cutting it balance wise.
No, I'm not a Rengar main. I have played him in all his forms, and quite frankly, it's beginning to become overly obvious that Riot wants to avoid certain designs for Rengar, and players simply want a revert because of other reasons. Find a middle ground and work from there. His old kit won't cut it, but that doesn't mean you have to scrap everything.