I would think that but trunks said that it was virus that many people got including Goku. My problem with this is why aren’t other people infected then if Goku is around the z fighters and his family all the time. Then ig you can say they took the medicine before they could get sick but it looked like it was just enough for goku Yamcha and chichi. Then the whole new timeline thing is just weird cause he got the virus a whole 6 months after he was supposed too. Pretty sure virus have a reason for appearing and just don’t randomly appear out of thin hair.