That is total BS.
“Not Approvable” letters meant that the FDA had refused to allow a drug to go to market and the interaction between the FDA and the applicant on that application was completed, and if the applicant decided to continue developing that drug, when ready the process of applying for market entry would begin anew. In the instance of an approvable letter, the applicant was free to continue his efforts for subsequent drug approval by the FDA working on the criteria noted in the letter. This letter most closely resembles the current CRL process. Regardless, the type of letter had a potentially significant real-world impact on the applicant, completely separate from the application’s status with the FDA.