The "hashed together at the last minute" explanation can't be correct: 7th ed. integrates too many things we've been seeing since at least the release of Apocalypse (Dataslates, Supplements (with variant lists like Farsight Enclaves or Inquisitorial Detachments, which didn't have Troops), Escalation and Stronghold Assault). This edition's been in gestation for at least a year. "After the financial report" is too slight a window, and the dots of all the last year or so's releases join too neatly for 7th to have been a last-minute rushjob.
I could be wrong, but I bet I'm not.