One of my creditors removed one of my positive trade lines this week, dropping my total number of accounts from 22 to 21 on my reports. While my EX score remained unchanged, my TU score dropped 4 points and my EQ score dropped 2 points.
I reached out to the creditor and am 50/50 on if they'll re-report that tradeline again for me, but if so and I get back those 4 and 2 points it will confirm that the presence of that account (or lack of) resulted in the slight scoring change.
I didn't think that removing a positive account would have an impact on a non-thin file. I suppose you learn something new every day 
Oh and the removal of this account didn't result in a AAoA reduction BTW; the age of the account was younger than my AAoA and increased it by a month it appears which is irrelevant to scoring.