It is always a good practice to create a thread on the basis of AOR and not on ITA.
Actually all those who have received ITA today will not submit the application (eAPR) in the month of February itself, few may submit in March and it could also happen that few will submit in the month of April.
Also as the total processing time (as stated by CIC) is counted from the day of AOR (which is essentially the same day as of eAPR submission), it makes more sense to group on the basis of eAPR/AOR and not on ITA date.