Do you want to be notified when they open or just at some point if they are open? The former is easy to do with a rule. The latter is possible with a rule but can get tedious to write if you have more than a few devices. I wrote an app to handle that case if you are interested: [RELEASE] Device Status Announcer (TTS or notification if lock unlocked, door/window open, etc.)
On a related note, the fact that these are Somfy shades in particular shouldn't matter. Hubitat drivers (what talk to the device and present the interface you see on the device detail page, more or less) categorize device functionality into "capabilities" that group together related commands and attributes, regardless of protocol, brand, etc. So, any solution you find for one type of shade should work similarly for another.
