The update is being rolled out exclusively in the US on the Verizon network. However the update has already rolled out on T-Mobile for Galaxy Watch 5 series.
IMG: Samsung
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New firmware version for Galaxy Watch 4: R865USQU1GWB2 (40mm)R875USQU1GWB2 (44mm)
IMG: Samsung
New firmware version for Galaxy Watch 4 Classic: R885USQU1GWB2 (42mm)R895USQU1GWB2 (46mm)