My biggest concern with the article is the fact that it implies that these new mechanics (battle/siege) are only for one expansion + cycle.
Which means that the previous mechanics (secrecy) are also only for one cycle - which is okay in the case of battle/siege, which can be applied as it makes sense. But secrecy is the kind of deck building concept that needs constant support throughout the life of the game to maintain (or arguably to become) viable.
We really need secrecy keyworded cards to be released at a reasonable rate (2-3 per cycle, + 1 per expansion perhaps) to make it a viable compared to just having 3 heroes. Otherwise it will become increasingly poor.
Alternatively more fetch cards (that are cheap) might make it work better, even just a cost 0 or 1 card that said, search your deck for a secrecy keyword card and put it into your hand. (This would enable you to increase the hit rate on important cards before you go over 20 threat).
Edit: On the other hand I really like the look of this expansion + cycle, I think it will be great, but I was hoping for more sustained support rather than bursts of support for one theme then another.