I don't go to McDonalds so I don't have enough information to answer to the 2nd.
On the first two, IMHO: The "blind bags" are not gambling because at least the ones I know contain a given value of items (+/- a bit) you just don't know which ones. And in no case would you get an empty bad.
For CCG I wouldn't even claim that they aren't gambling. It's somewhere on the edge because what you get has a utility value - you can play a game with the cards. And rare cards are often better cards for the game as well. So while I'm sure some people buy the cards purely to trade them, there are a lot of people who buy them to play with them.
You can say the same thing about loot boxes. However, the people selling you the loot boxes and the people running the marketplace for them and the people running the game they can be used in are all the same people. That means your entire process is at the mercy of the party running the game. Which is basically the same thing for casinos, so I don't see why the virtual casino should be different.