What does it matter what they call any of these shows? The format is nearly identical for all of them. A white guy in a suit comes on, does a short stand up routine, introduces his band, and they go commercials. When they come back, the host is behind a desk. He interviews big stars, but rarely asks any of them the types of questions we'd really like to hear answered.
Even when Leno asked Hugh Grant, "what were you thinking?" with regard to the tranny hooker, it was pretty clear that it was scripted for Grant to do his public apology.
Mix in a few sketches, sometimes a musical guest, lots more commercials, and show over.