From what I have seen of Moore, he is a great skater and passer, very similar to Constantinou in that regard. The former is unwilling to engage physically and often gets caught too deep in the offensive end. Both players have an average shot. If either makes the NHL, it will be on the strength of their mobility and passing ability.
As hockeypops said, Billy addressed a lot of his defensive issues and really shined in the offensive end. Being top 10 in defense points as an 18 year old is going to get a player noticed.
Other recent players to accomplish the same feat are Thomas Harley, Ryan Merkley, Bode Wilde, Tyler Tucker, Adam Boqvist, Evan Bouchard, and Conor Timmins. That's some impressive company.