From the International Council meeting minutes in December:
14. XL Sail development.
The Council was split on this matter, some definitely against others more supportive, a narrow vote resulted in a compromise decision was that:
The US be invited to test jibs up to 4.6sqm and spinnakers up to 23sqm only for crews weighing 175 kg and over. Every sail made must be registered and clearly marked “XL”, so it is known how many are made, where and when.
The XL sails cannot be used in National or International events for two years until further information is available.
However this subject led to further discussion and a paper presented by the Netherlands thought that the problem of varying weight might be one of perception more than reality. The meeting requested a detailed examination of the current weights of crews and sail areas. The Chief Measurer agreed to do some evaluation of the crew weight effect on performance. F18 have substantial statistics due to care in recording at Worlds from 2007 to 2013. The matter to be investigated and is ongoing.
Frankly I am a little-bit concerned that an unintended consequence of this may be a shifting of the ideal weight rather than just expanding to a larger demographic (the latter I'm all for).