No it's widely open as anyone can apply for a Global Entry card and pay $100 for the background check. If you're not a GE user then yes right now it's elite frequent fliers only, but that was partly by design - folks that fly frequently will both gain the most and be the most frequent to not be extra traffic in the regular lines.
The thing trusted traveler users are complaining about is that there's a random element to it - you can be sent to the regular security and still have to take your shoes off and go through the x-ray etc. So you can't count on saving that 10 minutes every time. I'm a Global Entry user, which has been great returning from abroad, but have never had the nod for the expedited screening line yet (0 for 4), and wouldn't want to time things close enough for ten minutes to make a difference anyhow. When I finally do get to go that way it's just a few more minutes in the lounge I guess.
It has to be one of the first things because they want to use it to weed out the test memorizing people paid to take the lab by the companies that then sell lab cheat sheets/ non-honest classes. It's only another hoop for those people to jump through but it may make a dent for a time.
In theory they can't lay off a ton of people in the US without pushing the H1B's out the door first - but it's unlikely they'll want to lose a bunch of their most cost effective workers. Be interesting to see what happens, they could have layoffs without layoffs (say it's all performance based), or the US could escape most of the cuts while the rest of the world gets layoffs. Suspect we'll see soon.
"Spock, did you see the looks on their faces?" "Yes, Captain, a sort of vacant contentment."