Probably not. DSS had a similar policy for years but no actual training or policy on how to use warning shots, which defacto made them unauthorized outside of specific scenarios ala early-to-mid OEF and OIF where the mission firearms policy would allow warning shots at vehicles simply for failing to yield to the motorcade prior to shooting the vehicle/occupants.
In 2023, the administration's EO that mandated more uniform UOF policies across federal LE (duty to intervene in excessive force, bar on chokeholds and neck restraints, etc etc) resulted in the loss of warning shots. I imagine it is the same for the Service.