Details on the changes can be found here: https://rust.facepunch.com/news/r-u-s-t#RustChanges
It appears facepunch maybe cracking down on some features that proved beneficial to those who have been gaining what they deem an unfair advantage from third-party apps.
It's unfortunate but does seem fair. Rust+ is a nice thing for those of us who have a life outside of rust and can't be at our desks 24/7 guarding from offliners but it would be unfair to use some kind of addon to get alerts whilst inside the game.
That's one of the reasons you can no longer use the CCTV cameras whilst being online, in the game world. So you can't use the cams to see where enemies might be.
The CCTV camera isn't 100% usable tbh I hate it but I can see where people might gain an advantage over others.