Will gach, cubes etc. soon become illegal?

While gachapon would be directly affected by this measure, there are dozens of ways nexon can pass off cubes as not "gambling"

Yes, there's a way but that doesn't always mean they will get away with it. If anything cubes are worse because some items in gacha aren't only gacha items where you don't NEED to gacha in order to get that item so now it's not really gambling you just choose to take the risk instead getting the item without spending money. Cubes is the only way you can get a scrolled items and/or unique items to the stats you like, pretty much rolling dice in a casino and try to get double sixes and paying each time you roll a die. It's literally the same thing.