There's no way to view this in-game and it's unlikely to be added back in again. Information is definitely outdated and you shouldn't really take it to heart.
There are a few trains, that were removed from SCR. Below, you can find a short description of them.
Main article: Class 345
The Class 345 Aventra trains were used for testing on Airlink. These trains were 7 cars in length, with a maximum speed of 90 MPH. These trains were never put into regular service, and they were withdrawn from testing without any further announcements regarding these units.
Main article: Class 700
The Class 700 Desiro City is an electric multiple-unit manufactured by Siemens, formerly in use on Stepford Connect. These trains were formed of 6 coaches, and were free to use.
These units were replaced because 6 car Class 700s do not exist in real life.
Main article: Class 701
The Class 701 Aventra train was used for Waterline services before it was removed. These trains were 4 cars in length and had a maximum speed of 100 MPH. This train costed 3000 points. These trains are no longer in service and cannot be purchased nor spawned. It was originally thought that the train was under refurbishment, but it has been over a year since they were pulled from service and Next Generation trains have been built since then.
- Express is the only operator without a train being removed.