Rumor holds there is only one more order book coming out this year, and given free peoples don't have a book, the new Aelves are rumored, and Kharadron are horribly in need of an update (plus Idoneth just got updated in GHB19), I feel pretty good about it having some staying power.
Every single other issue that you bring up is correct, and I agree, however, so... if someone wants to do it, I think you get to play it for a while and can feel good about that, assuming it works with the new Sylvaneth as well. Downside: it may eventually go away and it's not super competitive.