It is "intentional", as it is a product of how angular handles ng-repeat. Essentially, multiple copies of the markup are cloned (the markup inside ng-repeat is used as a template) and are compiled individually for each element you are iterating. As such, angular is basically compiling 3 <li ng-switch-when='1' ....>
and 3 <li ng-switch-default ....>
, but doing so out of context - there is no ng-switch-on element to compare to.
You can see this happening by inspecting the resulting markup:
<ul ng-switch="" on="toggle">
<!-- ngRepeat: entry in array -->
<!-- ngSwitchWhen: 1 -->
<!-- ngSwitchWhen: 1 -->
<!-- ngSwitchWhen: 1 -->
<!-- ngRepeat: entry in array -->
<!-- ngSwitchDefault: -->
<!-- ngSwitchDefault: -->
<!-- ngSwitchDefault: -->
</ul>
Both directives - ng-repeat and ng-switch - should be handled with care, as they (unlike, for instance, ng-show or ng-hide) heavily influence structure. The second (working) Plunker is the way to go - only work with directives AFTER (structure-wise, INSIDE) the ng-switch logic.