I have yet to confirm this, my friend as I was stuck on this HA10 research. Had I known that to happen, I really would have researched other HA levels before going to researching HA10. I dunno if, say you finished researching HA6 and then research HA10, one can immediately queue in HA6 while waiting for HA10 to finish researching. I hope others can clarify on this as this is good info to have on other players.
Lol. I was thinking that this is for us to be reminded of the best family alliance in the game. Made me think to create a new alliance: Seven Days Retraining or Seven Days Waiting… just joking, guys.