They're speaking of completely separate universes lying outside the inflationary bubble that we inhabit.Then, if true, our universe consists of more than one inflationary bubble. Uni means one. Whatever exists is part of our universe.
The rest sounds like semantics, yes?
There are several ways of talking about this. I kind of like cosmic bubbles (or Guth's pocket universes). Linde speaks of thermalized regions. The general idea seems to be that we inhabit a single inflating region within a much vaster (perhaps infinite) realm filled with (perhaps infinitely many) inflating regions and also (perhaps infinitely many) regions that aren't yet inflating. Each inflating region has its own set of fundamental physical constants, and, depending on the values of those constants, life-forms of one sort or another may or may not be possible therein.
It's a grand vision. But is it true? We don't know yet, and maybe we'll never know. In physics, there are no guarantees of access to evidence.