According to the release notes for the software upgrade currently in the final stages of beta testing, watchOS 9.4 will incorporate a modification that will prevent Apple Watch users from inadvertently turning off their alarm while asleep.
With watchOS 9.4, a wake-up alarm set to Sleep Focus mode will no longer be muted using the “Cover to Mute” motion. This is one of the specific changes that Apple has announced. This means that even if you accidentally muffle your alarm by covering the display of your Apple Watch with the palm of your hand for three seconds while you are asleep, the alarm will no longer be turned off.
watchOS 9.4 is anticipated to be made available to the general public as soon as the next week. An earlier post on Reddit drew attention to the relatively insignificant yet beneficial modification.