Quote: Graham Richards "Why does RL in Australia need promoting by British footballers. I will bow down to your superior knowledge on this matter once I have a sensible answer to my question.'"
Because rugby league in Australia is in a close neck and neck contest with Australian Rules to be the most popular winter sport and "football" code in Australia. It is also in a struggle with rugby union, which is the third winter sport in terms of attendances, and which claims to be the more international code of rugby (which it is).
This presence of the much esteemed Manchester United soccer players (who will play an Australian A League Selection to a sold out crowd of 83,000 at ANZ Stadium on Saturday) at the marquee rugby league event in Australia is a way of the NRL scoring prestige points against the rival codes in Australia.
The secondary idea was also to provide visual material to promote the World Cup. But that is up to the RFL to exploit. Hence my question in the OP.