You think so? When I first saw him in late 2017 "special" is what I immediately thought, reminded me of MacKinnon and I hadn't seen anything alike in a Finnish player ever before.
But a player born first of January for example, would be 2 weeks younger but would be a double underager. So yeah, Lambert isn't one, but you can probably make some comparisons as if he was one. For example if Matthew Savoie played in the same tournament, you'd probably compare them to one another rather than considering Lambert a year older(When he's less than 2 weeks older).