It sounds like the bigger factor isn't AAoA here, but rather AoOA. Your AoOA dropping from 5.x years to 1.x years is significant, as it suggests you have 5X less history/experience with credit. That of course can impact your score. AAoA no doubt drops as well once your oldest account is removed, but that's secondary to AoOA IMO.
This is al so confusing. When it hit EX and EQ my scores dropped like a rock; almost 100 points each. I got it corrected within 2 months time and I thought they'd bounce back as significantly as they dropped. EX and EQ bounced back 25 points or so, but TU(where it didn't report) actually dropped 20.
TBH, I'm just hoping none of my CC take AA.