Prove to us that you lost exactly what you said. Can you?

What if you said you accidentally dropped a stack of beacons? What if the guardian farm swallowed your whole vault? You see?

That’s why the rule is here. The entity cap is here for a good reason, it’s not really a bug. All the examples you provided us with, no, you would likely not get your items back unless it’s a very special situation. Sorry that you lost your sword though.