Good news! These models were shipped with an approved Hello sensor and an update is currently being rolled out from Microsoft to enable use with Windows Hello.
Alienware m15 R3
Alienware m17 R3
Alienware Area 51m R2
For 19xx H1, patch KB4577062, Windows build 18362.1110
For 20xx H1, patch KB4577063, Windows build 19041.546