"Unanticipated benefits" refers to unexpected advantages or positive outcomes that occur as a result of something, even though they were not originally planned or predicted. Full definition
The study found that — awkward or not — the networking was worthwhile and that executives reaped several unanticipated benefits by reaching out. (inc.com)
We have found that when assistive technology is offered to everyone, unanticipated benefits ensue. (educationworld.com)