I use the google home assistant and google knows more about my openHAB setup than me using telegram.
You just put something on my todo list, thanks for the idea.
Looking at https://www.shodan.io/ I guess some people need to stop allowing everyone access to their openHAB.
This is why I have more than one type of lock on my door. I see where you are coming from.
I use Telegram because it was easy to implement and it uses https. It would take a committed person to be able to intercept a message and do something like turn my lights on.
You can change the privacy settings for your phone and not add any contacts in so no one knows you use telegram.
I think leveraging off others vast knowledge is an excellent idea.
If you want to make a new binding then go for it.
If you want to add the functionality you need to the cloud connector and the app, please document it well.