So after reading the chapter i figured two things:
1 - aizen let those arrancar get killed seemed like they were no longer useful anyways.
2 - ulquiorra is still in the box which is kinda weird by now
Well when mayuri v szayel was happening , zael said he was fighting for about an hour, lets say it has been 15-20 mins after that we are up to this point
So after reading the chapter i figured two things:
1 - aizen let those arrancar get killed seemed like they were no longer useful anyways.
2 - ulquiorra is still in the box which is kinda weird by now
ulquiorra's like the hard working employee that does everything to get a promotion and does his fancy projects with excel spreadsheets and venn diagrams, only to be 1upped by the stoner in the office thats mad chill about everything and fucks secretaries on his lunch break...poor ulquiorra