That's exactly what he's saying. If it is written as wave data, it cannot be bigger than 2 GB. He's not talking about the bit depth of the recorded file, but rather of the file type itself.
In order to have a single file bigger than 2 GB, it must be in some other format such as W64 or SDII extended. I don't know if W64 has a limit, but I think SDII extended has a 6 GB limit.