…thanks for the pointer. I’ve revised the documentation.
One property of util:if was that you could omit the argument for the else branch. We decided to drop util:if, because the specification now provides a new syntax for if expressions where the else branch is optional:
if ($test) { $then }
if ($test) { $then } else { $else }
The ternary operator was temporarily added to the spec as an official feature, but we eventually dropped it again to reduce the number of different notations for existing features (unfortunately, the popular A ? B : C syntax was no option, as ? is already used for lookups).