I'm curious if you have some references about this, if you have read good blog posts or something ! I can think of Rust that does not have exception, but it's not because they didn't address the problem of error handling: exception are replaced by `Result`, if I'm not wrong. In Oberon there's simply no error handling mechanism.
There's nothing preventing you to use a Result type in Oberon. Just not as a fancy algebraic data type, but rather as a regular record/struct type.