London has one faint ray of hope: that Super League decides to expand to 14 in 2020, and adds Toronto and Toulouse, with no existing Super League club being dropped. That would be the best outcome for the future appeal of Super League, because the competition needs a club from London, as well as Toronto and Toulouse.
I prefer licencing as a rational business model for rugby league anyway. But if they still want to revert to promotion and relegation in 2020 season, Salford is likely to be the one to drop, since Salford is going to going to lose Robert Lui (Hull KR) and Jackson Hastings (Wigan) at the end of this season.
Whatever the decision on licencing vs promotion and relegation, Super League should leave open the possibility of future enlargement to 16, with New York and Ottawa being added within 3-5 years..