Awe, that's a bummer for sure! I love pearl gouramis. Low chance of aggression with them, they don't get too big and they're super cool looking. In regards to the untimely death, like said above, that's something that seems to effect the community tank, especially when new stock is added or live foods added, etc.
I lost my 4yr/old female pearl gourami some months ago. Found her on the floor behind the tank, completely dried out. Must have gotten spooked and shot out in one of the small gaps behind my glass tops.