Yes.  If `options.fetch` was a command method like so:

``` ruby
options.fetch :call_site, CallerFilter.first_non_rspec_line
```

(...notice no assignment), I'd be fine with it, but given that it's a query method that returns a value, I think it's better to use parens.  If you think about it, the main place the community omits parens is in DSLs for methods that have side effects (e.g. because they define a method or example or whatever).