Rhyme King would understand this but since he's not here I'm going to have to explain it
When a rapper is rapping and you can predict the upcoming rhyme from a mile away there's a mental dopamine effect taking place in your brains reward center and you get that small dopamine reward with the rhyme confirming your prediction . . however when he removes that rhyme . . in your brain you had telegraphed a rhyme and you never get the reward so it's kinda like your mind is playing a game with it. Now by not rhyming he makes the non-rhyming word that takes the place of the rhyming word a more eventful surprise.
It's really genius . . because you have the listener rhyming in their head on a subconscious level and you have a surprise for them every time