For a trip this complicated — and any time you're looking for premium cabin award seats for more than 1 person — that timeframe is normal and strongly suggested. (upgradedpoints.com)
The change in aircraft could have an effect on premium cabin award availability too... but not necessarily for the worse. (travelingformiles.com)
It's just a very tough pill to swallow for those of us who do love redeeming for premium cabins on partner airlines, and are involved in this hobby for that reason. (mommypoints.boardingarea.com)