User presence is defined in present time. There are no FIDO police who'll burn down your factory or arrest your executives if your device doesn't do this, but removing this safeguard has (at least potentially) negative consequences.
I believe some theoretical attacks against user privacy would benefit from being able to attempt a huge number of "authentication" steps without annoying the human by making them touch the sensor. As with the Socialist Millionaire's Protocol or Magic Wormhole, we're relying on the fact that humans get annoyed fairly quickly and will just give up if it doesn't work, so attacks that require a large number of iterations cannot mechanically succeed.
I believe some theoretical attacks against user privacy would benefit from being able to attempt a huge number of "authentication" steps without annoying the human by making them touch the sensor. As with the Socialist Millionaire's Protocol or Magic Wormhole, we're relying on the fact that humans get annoyed fairly quickly and will just give up if it doesn't work, so attacks that require a large number of iterations cannot mechanically succeed.