This is probably worth a read for any competitive Blood Bowl players / tournament organisers:
In short, it looks like NAF will annually review all GW releases and see which ones they want to include in the NAF rules. This will be updated every November and be enforced every following January.
Games Workshop releases in between Novembers will be considered optional for the various tourney organisers.
This means that NAF will invariably “lag behind” GDub - something to be aware of. e.g. if GDub release something December 2018, it will only be enforced by NAF Jan 2020(!) at the earliest.
Overall it is probably a good thing that NAF are doing this. It should lower the level of confusion at tournaments.
Block ‘n’ Roll!