If you look up the definition for gambling, I think no matter how you twist it, it does require a stake of some sort. Money is one thing here but you could as well use your car or a watch, but if nothing of value is involved, how could it fulfill the definition of gambling?
Even if you take this definition "take risky action in the hope of a desired result", it doesn't mention the word money here, but there is a risk and a desired result. If you predict an outcome but there is zero at stake, what's the risk then? If there is absolutely nothing at stake, it makes semantically no sense to call something a gamble. As I said before, it could even be your reputation. Let's assume you run a channel that predicts weather and you are totally off, then you would still have something very important at stake. Assume you predict the weather for a Sunday in two weeks from now and if you are right, new users will consider following you. If you are wrong, you may lose followers. That's when money is not involved as a direct means, but as a mid or long term consequence of your predictions being right or wrong.