Empty Platform Condition—Bug?

I was testing some code just now and turning a condition on and off for various platforms by commenting them out of the list.

.when(platforms: [
  //.macOS,
  //.windows,
  //.linux,
])

In the above state, what is SwiftPM expected to do?

At the moment it makes the condition universally true (during loading, the empty array is unified with a nil condition). Is this a bug?