If you have a watch that was imported into the US before the restriction went into effect, you never lost the (original, watch-only) Blood Oxygen functionality and this update doesn't affect you.
Up to mid-2024, Costco was selling 2 separate SKUs of Apple Watch Ultra 2: watches with the blood oxygen feature and watches imported after the cutoff which were missing the feature.
A limitation of this workaround is that it only works on recent watches. If you are in the unfortunate position of getting a Series 6, 7, 8 watch replaced by Apple, they'll give you a replacement with the feature missing, and this update doesn't "fix" it..
Up to mid-2024, Costco was selling 2 separate SKUs of Apple Watch Ultra 2: watches with the blood oxygen feature and watches imported after the cutoff which were missing the feature.
A limitation of this workaround is that it only works on recent watches. If you are in the unfortunate position of getting a Series 6, 7, 8 watch replaced by Apple, they'll give you a replacement with the feature missing, and this update doesn't "fix" it..