I read the story. It says: "Luckily Liam’s friend has supported him through this but is only able to visit him for an hour a day so we know nothing about the other 23 hours of his time/ treatment."
It does not say the hospital is limiting visitation, it only says that the friend is only able to visit him for an hour a day. It has been my experience that Thai hospitals are generally very accommodating with visitors.
In any event, if Liam is in the ICU, it makes sense that visitation would be very limited, if allowed at all.