As I said, there has been no change in policy with regards to tier mile earning timeframes. Miles have always only been credited after a segment is flown. You may have miscalculated your requalification period, or perhaps it is due to the rolling requalification threshold. If your requalification is 31 August, and you are short, you drop down one tier, if from the previous September until this 30 September you have sufficient miles to regain your status you will retain it, as there is also a 2-month grace period (requalification date of 31 August means your status is valid until 31 October, so you could technically have insufficient tier miles to requalify in August, but still requalify before you lose your status, thus not experiencing any gap in status).

Unlike major US carriers EK assesses status on a rolling 13-month window and you can regain status at any point after the end of your status year as long as the preceding 13 months have sufficient miles.