It makes as much sense as the first time that Eiko had the dream. Ika is invading people's dreams, one at a time. Why Gorou dreamt about Eiko (instead of Chizuru) is the question, and it's the same reason that Sanae expressed her distress that the dream didn't have her in it, but had Eiko as well. It's a running gag.
Ultimately, I'm with Kraco. It was nice the first few times, but if they're going to keep doing it ever third episode, it is going to get stale fast.