If we’re in a simulation then we’d have no idea what’s outside that simulation, so we’d have no idea what an easter egg would look like.

But it’s not my job to find evidence to prove other people’s claims. It’s their job to provide evidence for those claims. That’s true regardless of whether the claim is that we live in a simulation, that we’re ruled over by a benevolent omnipotent god, or whether there’s a teapot orbiting between Mars and the sun.