Spot on. I received a small ($150k) NSF grant back in 2010 and made a semi-popular science education app/game for iPad. It was featured by Apple a few times and was even in an iPad commercial - it made basically no money.
I'm actually still working on something similar but, basically, no longer trying to run a business selling educational games (more, profits from commercial development contracts with actual budgets funding the cooler projects).
I was unable to find anything specific beyond "apps we determine to be outdated" here https://developer.apple.com/support/app-store-improvements/
(note: I am not OP)