Its really too early to make a conclusion like this. Like they said in the video, the internet was being used by people all around them too. Also I'm sure it plays with even less latency when using a direct connection to the PS4, rather than going through the router.
Is there any sort of confirmation they were going through the router? I would assume they would just skip that hassle and go directly to the ps4, in which case I don't understand why network interference would be a latency issue for one game but not the other.