The first statement of the NBA preseason was made by the Toronto Raptors, one that came even before Kevin Durant made his unofficial debut with the Golden State Warriors. The Raptors' players and coaches linked arms during the playing of the American and Canadian national anthems Saturday night, their statement serving as the latest entry in a widespread series of protests across sports in recent weeks designed to raise awareness of racial injustice and other social problems. ''Guys were real, guys had sincere feelings, sincere thoughts, sincere things to talk about and concerns,'' Raptors coach Dwane Casey said before the game.