FAA's AC-61-138A addresses the academic guidelines. It's the opposite of discouraging advanced training. Instead it addresses areas that people pursuing their ATP's might have no clue about. The ARC (Aviation Rulemaking Committee) had representatitves from 9 areas get together and hash out what they thought new ATP's need to have awareness of. I just read the 10 pages of academic subjects and thought it was a pretty good foundation for low time pilots moving forward.

Pages 10-20 have the subject areas to cover -

https://www.faa.gov/documentLibrary/...AC_61-138A.pdf