My groups played Rotary Flensing Saws as you can move up, but you must maintain the original distance you had from the target before the knockback. Just as otherwise you have Corpse Grinders catapulting themselves about the table.
But its also relevant for Coup De Grace - as it allows a Versatile weapon to do that when they otherwise couldn't by allowing an attacker to move into base to base - negating one of the main drawbacks of Versatile.
So, yeah, if you play it RAW you can move the attacker in to base to base then what results is models bounding across the board, killing enemies without any chance of Retaliation attacks. ...Which the Corpse Grinders already do with their good Close Combat stats, but at least there's some extra hurdles.
I've honestly no idea if that was the writer's intent or if this is seemingly another case of them not knowing their own rules (and just going "that seems cool").