I don't interpret what she says as 'he doesn't apply himself' to be honest, well not in the way you mean it. I don't think it means he's never going to learn the value of hard work, or the thrill of discovering something new. He's very young still, he probably isn't even aware that he's learning iyswim. Not at this age, especially if things come easily to him.
I'd take it at face value I think. He does what's expected of him, the immediate challenge, and then moves on without thinking it through any more or being all that curious about what he's presented with.
I think smee's bored / attention comment is a good one. I wish someone had pointed that out to me when ds1 was in reception.
I'd hold out until year one, make sure he has loads of fun and interesting things to do at home, encourage his friendships and sense of fun, enjoyment of school which isn't based around work.