If we're honest with ourselves though, while we're arguing your hypothetical, we both know the Government can modify and legislate what they decide to define as gambling.
Aye, I live in a state with video poker machines at every corner gas station.
My point isn't to redefine what is/isn't gambling, but to point out that this particular ESRB Ruling makes no sense whatsoever. The determination shouldn't be if you get *something* back (even if it's something you don't want). As I'm sure we can all agree, if I to a raffle where one lucky winner gets $1m and everyone else gets a ziploc baggie of dog turds, it's absolutely gambling.
I guarantee that if the ESRB sticks with this ruling and companies continue down this path, we will absolutely see an attempt at regulation here.
As folks have come up with talking about trading cards, lottery tickets, poker, McDonald's, casinos, etc. - each of these things have pretty clear odds and many have third-party (if not government) oversight into the execution of these programs.
Right now, I could sell a game with 'loot boxes' where I claim there's a Golden Armor of Awesomess, which is the sweetest armor in the game. I could say the only way to get it is in Loot Boxes, I could say it's in One out of every 1,000 boxes, but I could really tinker with the odds so it's in one out of every 10,000 boxes and absolutely no one would know.
There has been a few lawsuits over the years claiming that trading cards are gambling, but I haven't been able to find anything aside from mentions of them being dismissed - Nothing about what grounds they were dismissed on or anything. It'd be interesting to see this in court with digital goods. At least with trading cards, you have somehing you own. With digital goods, you have a license that is as good as the company says it is. :/