I once had three full-grown Amano shrimp hiding in my aquarium for over a year and I never saw them. I had a
goldfish in the tank that liked eating inverts, and I eventually presumed that he'd gotten to the Amano.
Last year, I broke the tank down to add a
UGF, and found the shrimp. They had remained hiding in the tank the entire time.
I learned two things from this.
#1, Amanos are extremely intelligent for having such a simple nervous system. They know, or can learn, what fish present a danger to them.
#2, Amanos are incredible hiders.
It is possible that your gourami ate them. If it got its mouth on one while they were molting, it would love to snack on them. However, they are fast, they are smart, and they can hide. They're probably fine (though you'll likely not see them).