Apparently it does have a blood pressure measurment, "based on pulse wave velocity (PWV) method to estimate systolic and diastolic blood pressure".

>For accurate blood pressure readings, Samsung recommends that a calibration is required every four weeks with an arm cuff and blood pressure monitor, so be prepared to buy one of these to get the most out of tracking blood pressure on the Galaxy Watch. Users should also measure their blood pressure while at rest and not during a workout.

People have different experiences about the accuracy: https://eu.community.samsung.com/t5/wearables/blood-pressure-reliability-amp-accuracy/td-p/2925769

Anyway, OP might find this an interesting lead to follow.