From what I can recall I had a fairly similar experience a few weeks ago when I was routed to the Egyptian call centre and I requested to be moved to the earlier flight from LHR. First I was asked for the usual PNR + passenger name, email, phone number when they pulled the booking, followed by being asked for my aerclub number, date of birth and finally mother's maiden name to verify my Aerclub status. It seemed to me they were accessing two different systems, the whole interaction took longer than normal (around 15mins) and I asked if I could hang up, as they were still processing the change of flight. Email confirmation followed a few minutes after hanging up.

At the time, I found it very bizarre, but I didn't think too much of it as I was keen on getting my flight change processed. But I definitely agree that it's concerning.
Could it be that the Egyptian call centre has a different / more disparate access to the systems? Everything from verification to actioning the request felt very slow, and it's definitely not the first time. As mentioned above, the US agents are 100% on the ball and nothing ever takes more than a few mins (as it should).