It would be the antithesis of "strict tempo" for the music not to maintain its basic pulse, but quite frequently, a particular piece may have breaks in the melody line, where the beat carries on, and so does the dancing.
I have on CD in my own small collection which breaks the normal rule, and has a short pause, for musical effect, which interrupts the underlying pulse. As long as I remember it's coming, I can make something of it, but if it came in the middle of a double reverse spin, I'd be in trouble.
Such music is not really suitable for dancing, surely. By the same token, I wouldn't choose to listen to dance music, just as music: there is too much lost in the maintenance of strict tempo, compared with the best interpretations on purely musical terms, and our dance music is musically compromised, butit suits our purposes, by and large.