I love the idea of an automated resurfacer. The linked-to discussion suggests that a human adapts to ice conditions better - but that could be dealt with by sensors, just like some high tech tractors now have sophisticated sensing equipment to decide how much fertilizer, of what types, is needed on different spots of soil.
But the obvious problem would come if some kid is slow to get off the ice, and gets run over by the robot. Plus, at some rinks, some of the kids and adults already skate fast around the machine doing the ice (one of my ex-coaches liked to conduct lessons then, on the relatively uncrowded ice) - and the robot wouldn't be able to yell at them with sufficient authority to stay off.