There's a soft vent, as if Optimus wanted to continue the conversation, knowing full well that it would be an inappropriate time to do so. Still, this conversation WASN'T over, and he wanted Bee to be fully aware that it was going to pick up at a later time.

"This Cybertron is a different one compared to our own. But much that we know of it is still uncharted. Unaccounted for."

And if this was the state that the nearest civilization had been reduced to, safe to say he was worried about the rest of the planet.

"I'm thinking of taking a crew to investigate.