Some styles of delivery, like auction chant, use this technique for effect. Here the techniques of slurring filler words to make multiple filler word phrases is a key element. It appears that the auctioneer is talking fast, and this in turn generates excitement and anxiety (that their offer will be accepted or be in time) among the bidding crowd.
You can hear relaxed pronunciation in various singing styles too: current Vocoder use comes to mind. The effect of relaxed pronunciation countering a stressed line when reading is worth exploring too. A similar effect to an acoustic rendering of a line or two in the middle of a Led Zeppelin track.