As I understand it reference stall speed Vsr is the declared stall speed chosen by the manufacturer. It may not be lower than Vs1g which as has been said is the lowest speed for level flight.
During a stall demonstration the aircraft will experience less than 1g and this was when the lowest indicated speed was recorded in previous certifications.
The new requirements appear lower on the surface. 1.23 is lower than 1.3 but it's actually the same margin. 1.23Vs1g = 1.3 Vs.