It says that RISC OS ROMs can be released without having to pay a licence fee to RISCOS Ltd, but doesn't use the same language for the commercial licence.
Reading between the lines, it looks like ROL would take a portion of the ROOL's income from commercial licences. ROOL would make their profit from the remainder. That would require RISCOS Ltd to offer a licence.
As long as they have the right to do that, it seems completely reasonable.