Blood pressure has long been considered the "holy grail" of PPG-powered wearable tech. Because (up until now) you really need an inflatable cuff to measure, or at least to calibrate, blood pressure readings, and that's been difficult to do with a smartwatch alone.
The Huawei Watch D series incorporated a cuff into the smartwatch itself, while Apple has introduced its Hypertension Detection feature, which earmarks possible hypertension after 30 days of using an Apple Watch, but doesn't actually provide blood pressure readings. No LED-based device has really been able to crack it. Until now, apparently.
