You say potato I say potahto - and Dan Quail mispells it anyway.
The bass player with UOGB is just cutting up, though, when he calls his bass a bass uke. I've seen clips of shows where it's obvious he's joking about it - I think he started making that joke about the time he switched over from upright to the acoustic bass guitar (it's amazing how long most of those guys have been together).
I think they call the UBASS a uke bass simply because Kala built it using what is essentially a stock baritone uke in other respects. (Actually, they licensed it from the guy who created it, but the idea remains.) The UBASS is no more a uke than an Ashbory or other short-scale bass. Or, I suppose, we could say that they are no less a uke.
However, I think if you consider what
role an instrument plays, the UBASS has to be considered a bass, not a uke. It doesn't matter that it may physically resemble a baritone uke, it fullfills a completely different role than any that can reasonably be expected from a uke. A uke, even a baritone, is a high-register instrument used primarily to play melodies or rhythm comprised of strummed full chords. Yes, we can, and often do, play arpeggiated chords but that is not the ukes primary role.
A bass on the other hand rarely plays the melody and is rarely strummed with full chords. The bass is designed to lay down a groove "under" other instruments. The bass works with the drums to establish the rhythmic feel of a band, and assists other band members by signalling the coming of chord changes - those are its primary rolls. Sure, guys like Victor Wooten or the Ox can play it as a solo instrument but if they couldn't also lay down a steady groove to support a band they would not be "playing bass."
Claiming that a UBASS is a uke is kind of like claiming that a banjo is a drum because it has a skin head - it may have a skin head, and you might even be able to get some soft drum-like sounds if you mute the strings and tap it, but it's designed for a completely different role. Does this make sense or am I babbling again? LOL
John