I don’t believe a shortcut will let you disable/silence these notifications through settings, at least I found nothing to do this. Unless your security camera app has shortcut integration to do this. You could use a shortcut to cut your phones internet, although that would also stop other (emergency) notifications from reaching you, so likely not what you’re looking for.
You could add a “quiet sleep” focus and either use a shortcut (kind of like ‘run at 7:30, if focus is sleep, set focus to quiet sleep’) or just directly schedule it for 7:30 with the focus schedule. This might mean that your health app thinks you always wake up at 7:30 (not entirely sure if that is how it works), but when disabling the “quiet sleep” focus, you could then just log another health sample through shortcuts (as in ‘run if quiet sleep turned off, log health sample asleep from 7:30 to now’) and you’d get the same data.
I have had a lot of focuses, some that do almost the same thing but had to be split into different names just to make some scripting work. Splitting your sleep phases might be an option for you too.
I’m glad that suggestion would work for you! Yes, you’d only need to script the transition from sleep to quiet sleep at 7:30, that should do the trick. Maybe you’d want to switch the to focuses, as in having a ‘light sleep’ where you get notified by your cameras, and the switching to the normal ‘sleep’ focus at 7:30, because usually when I turn off the sleep focus, I have a weather forecast on the lockscreen, and this might not work if you turn off the ‘deep sleep’ focus instead. But you’ll figure something out! :)