It still exists according to the ECF at http://www.englishchess.org.uk/?page_id=21
16.0 Inclusion in the Rating list
16.4 On appearing in the FRL or FRRL, a player must, so long as he remains on either or both such lists, be a member of World Chess Club
There is no regulation 16. They go up to 13 which says
13.0. Inclusion in the Rating list.
13.1 To be included in the FRL or FIDE Rapidplay Rating list, a player must be a member of a national chess Federation which is a member of FIDE. That is, the Federation must not be temporarily or permanently excluded from membership.
13.2 It is the responsibility of national Federations to inform FIDE if players should not be included in the FRL, FRRL.
13.3 Any player excluded from either rating list because he is unable to obtain membership of a national Federation, my apply to FIDE for special dispensation to be included.
The website comes under Marketing, so factual reliability of the website is presumably now the responsibility of the chess-boxing guy.