Yes, there are quite a few examples of this. It`s definitely possible to predict, that takes a skilled eye or just dumb luck, but I was mainly referring to investing in sets in general. These highly sought after sets are few and far between, and absolutely there is the possibility to make a large amount of money. If you think you know of a set that will be in high demand like those listed, Minecraft, etc, absolutely stock up early. There is nothing wrong with holding sets longer, that depends on your personal amount of cash flow. If you can sink money in for longer periods of time comfortably, do it, that`s awesome Goes for anyone. Those sets you mentioned there had a reasonable shelf life. For some reason a small, for lack of better word, "bubble" formed around them and the price inflated very quickly. They were literally available 1 day and gone the next. People panicked and bought in.
I guess to directly answer your question, that opinion of mine doesn`t really fit the context of these kind of sets. More so for the general sets that will retire and gradually rise over time. There aren`t any 100% guarantees, it`s very much a combination of skill and gamble, but the rewards can be quite substantial if you do it right. I`m still earning myself, and that`s only one perspective. There are lots more, I`m just saying as a general rule, you want to buy sets as close to retirement as possible while trying to get the largest discounts. Not an absolute by any means, more so just a rule of thumb to apply with most sets.