Seems interesting but it looks like some cli with web server running on someone else's machine, so basically no security, no encryption. Also probably this bot have an access to your entire chat history.
The bot has access to any sent messages to yourself, plus any chatter in group chats if you have enabled that. So don't use it for sensitive stuff, and use a dedicated group. It was developed to relay sensor data and such, not war plans.
Now, I do not plan wars with Yemen but still want to keep my private conversations with my wife about my furniture, well... private. For solving notifications I can just do what I do now: selfhost matrix and apprise.
So the whole solution seems interesting, though I fail to see point of using it whatsoever.
If you could self host it yourself too? Yes but like that? No.