Hasn't that been the case for ages? Look at the sheer amount of weird branded cornflakes that were only available for one or two years. Hell, Smurf Berry Crunch was a thing in 1983. https://en.wikipedia.org/wiki/List_of_breakfast_cereals
Here it only started, noticed recently since I eat Quakers VERY often and the boxes are all tiny 375g ones which hardly last any (I literally have to eat like two boxes for breakfast), then there was a "limited edition" of them with a 450g pack for just 10 cents more, it's ridiculous! I get "family pack" or something, but seeing limited or special editions just feels weird AF!
As for microtransactions, they already did it of sorts, some time back in the US I heard about cereal with a video game attached and depending on which pack you got (increasingly expensive) you got more bonuses when playing the game...