I am credit to team!
So the way I’m reading it, the ruling on cascades is that they will still give extra turns even if they’re coming from a frozen troop’s ability - i.e. a transformer makes a match that lets another 4-match happen. In fact, all transformers that don’t fuel themselves, apparently. Shadow Dragon won’t work because it is purple, but Slime will work because it isn’t purple.
I definitely like the concept of its lower power allowing it to be more common and less expensive. For that matter, if that happens, it also allows for some stronger extra-turn troops to come in. But a major point is that we might avoid the relative uselessness of the burn effect and its counter, Fireproof. Nobody cares about Fireproof because there are only a handful of troops that burn and nobody runs them - but if Frozen is easier to get, then the counter trait will be nice.