With One being how he is, I had to feel there was a message in this ark. I believe it just boils down to honest communication and he uses a telepath being able to read thoughts even without his powers, Reigen cold reading that there was more to the story about researching the alien summoning, and the kidnapped member managing to get his desire to go back to Earth across to the Aliens despite never speaking their language. I also think that the Aliens they met were their own version of the telepathy club just hanging out and hoping to make contact with another race of beings. I'd say even that is a message he tried to put in to display that even across the stars you can find people with the same passion so long as you dedicate yourself to it and keep an open mind.
I'm really happy that they also adapted this part of his story because I honestly believe it's something that would have been skipped in the past or by other studios. The most "action" is just a small creature getting stomped and yet I feel there is so much of his philosophies and messages that One crammed in.