I thought I saw those too, but haven't been able to find them in the FAA notices for model aircraft. There is such a clause in the 2012 for small unmanned aircraft (sUAS) use by a "government public safety agency".
I would presume the FAA will try to apply such a rule to civil use after this ruling.
Edit: Federal Register Notice 14 CFR Part 91 says they "expect line of sight" for model aircraft. It does not seem to be required--and at least one administrative judge thinks that such a notice does not carry much weight.
Maybe I'm thinking of AMA requirements though... (think model airplanes, not doctors - although, doctors also require line of sight)