Does a hallucinated observer work as a detector?

I was reading a forum post on TeamLiquid where an interesting fact was posted.

"A possible solution to this would be to allow the sentry to create hallucinated observers which can function as detectors. They'd still be super squishy (essentially only 30 HP) and not cloaked, but it would also give Protoss something against cloaked banshee/observer snipe builds."

Does this already work or is it just a suggestion which should be implemented into the game?

Solution 1:

This is just a suggestion. Observers cannot be created as hallucinations, and neither can Dark Templars, Carriers, Motherships and Sentries.

If you could have hallucinated any sort of permanently-cloaked unit, by the way, it would have made that ability very strong for scouting.