Using /setblock on a redstone-mechanic block won't update the mechanism

^{Update by [Minecraft] Mega_Spud (Jay Wells):}
Summary:
Whenever I /setblock a Powered Lever on an Unpowered Lever, it won't activate the redstone mechanism next to it.

Steps to Reproduce:

1. Place a redstone lamp
2. Place a lever on the top of it
3. Stand on top and run the command: /setblock ~ ~ ~ lever 13

Observed Results:
The redstone lamp is still unpowered, even though there is now a powered lever on top.

Expected Results:
The powered lever should power the redstone lamp.

Screenshots/Videos attached: No

Notes:
If a powered lever is set with the command without replacing another lever, it will power the redstone lamp correctly.

Original Description:
Whenever I /setblock a Powered Lever on an Unpowered Lever, it won't activate the redstone mechanism next to it.