[truehappiness]

I think the Twitter statement isn't really just about the child being off limits, but them wanting privacy as a family. The song also could have not been released and this still would be something that she would have had to deal with eventually. IMO it is a bit of a leap in logic to assume that Ohia no Ki was somehow an invitation for people to pry but they would have been trying to find out more anyway since the day that she said she had a child back in January.