The instructions are correct but reflect some of Apple’s weirdness in iOS.
When you turn that on it then gives you the option to individually control app restrictions, and by default they are ALL ON still.
It also gives you ANOTHER option to restrict whether ANY apps can be deleted, not just Telegram. Why is this option is located here, when it makes no sense? Apple.
After setting it you would have to turn it off if you wish to delete ANY app, not just Telegram.
Who knows why Apple tends to bury useful settings, you would think that there would just be a switch in each individual app settings to block deletion of the individual app, and not make you dig into a setting tree that is unrelated to app deletion.
I agree that Apple could get rid of Telegram on its own if they wanted. However, I suspect that they want to look like they made an effort so they can still travel to Fascist France.
OK that makes sense. I forget sometimes that most people leave the defaults on. I set permissions on each and every app and always have.