Nonsense. You don't need to be a predator to be driven to expand territory. I suggest reading up on the "generalist specialist" theory of hominin evolution:
I think what’s being referred to is the Fermi Paradox which is a little more complicated than having to be an apex predator to get to space.
According to the theory set forth in Fermi’s view, all the races capable of interstellar travel evolved aeons ago and are constantly on the lookout for other species evolving to a point where they are capable of space-travel. When they find evidence of one, they extinguish it.
In other words, the apex predators are already out there, invisible and waiting to swat any fly that gets too big for its boots. Theoretically in order to protect their own interests then they just extinguish a given species parent star or whatever when a species starts looking lively.
YMMV of course. I don’t think anyone can state with any certainty to know for sure. Basically you don’t have to be an apex predator to get into space, but once you’re there it’s considered possibly wise to tread carefully and not make too much noise because it’s likely that not every species out there is friendly.
I think Stephen Hawking said we should be a lot quieter in the kinds of messages we send into the void because we don’t know that any given receiver is benign.
For further reading, Cixin Liu’s “Remembrance of Earth’s Past” is well worth a look.