The bass player, Corey Duplechin is playing/filling the bass-line "up-to-the-eyeballs."
I've downloaded that track and listening to it carefully. It's a (very) busy bass-line for that particular style(!).
And I mean, "busy" not only playing lots of various fill-ins but also, as changing so many the rhythmic-melodic bass patterns/templates/contours.
It's enough for 5 or 7 different songs that have a similar chord progression.
But...
The bass is "quiet" in the overall band's mix; therefore, a lot of "variations" are not noticed easily.
N.B. It's only my opinion.