I talked to Frontline via their FB page and it turns out it's not their fault; they adopted the Adepticon 7th ed. FAQ which has a few holes in it (though IDK to what extent the Frontline people maybe had input on that FAQ).

I think there are a handful of things other people are looking at and are skeptical about, but I haven't really followed that; for me the thing that sticks out like a huge sore thumb is that the Adepticon FAQ has a component that is a mistake by RAW that is a huge blow to Daemon armies, which is the main thing I bring to a serious tournament and was what I had been practicing for WGC.

I originally thought this was some arbitrary stealth balance change that had been implemented by Frontline even though it contradicts the rulebook, but on the Adepticon FAQ it says: "Players should pay special attention to bullets that begin with, “For ease of tournament play, at this event...” These bullet s repr esent the most significant clarifications and in some instances direct changes to the existing rules." ...and this change doesn't have that qualify, so that means the Adepticon people just got the wrong rule.

The change in question is:

"A Psyker with a Mark of Chaos or a Daemon of a particular God cannot benefit from the general Psychic Focus rule."
That's completely in contradiction to the Psychic Focus and Chaos Psychic Focus rules in the case of Chaos Daemon Psykers (though as everyone knows, CSM are forced in their codex to generate at least 1 roll on those tables). It's a huge kick in the gut to Chaos Daemon armies with summoning, and to an extent also to flying circus armies. This single-handily means I will probably not bother bringing the army I've spent the last few months practicing and finishing the sculpting/magnetizing on.

I had thought this issue was settled within a week or two of 7th being released and people realizing that both rules apply to CDs, and no tournament I've been to in the last year in any 3 TX cities did it otherwise. So it was a real shock to see today that this was in the Adepticon FAQ.