I suspect they've done so earlier but yesterday I discovered the first evidence of a molted shrimp. Unable to take a decent pic because the old shell is lying in a dense patch of plants but it's there. Looks just like a shrimp has taken it's coat of.
I also have two females carrying eggs. Curious to see when they will hatch.
The tetras are still doing fine, only the lone male guppy is feeling a bit alone. He's still trying to impress the gold tetras because they're the closest thing to a female guppy.