RE: De Novo Application Timeline (FDA)

Hi, on the FDA’s own website re de novo applications, I see that the decision times are usually around 120 days or, if they go over, 150 days in which the FDA would inform the applicant what issues are causing the delay:

https://www.fda.gov/media/107652/download

However, with some companies, for example, INVO Bioscience’s de novo application for its INVOcell, it took way longer than 150 days (the application was sent on Feb 23, 2015 and the decision came on November 2, 2015).  

My question is this:  what are the July 1, 2015 and July 6, 2015 dates in the November 2, 2015 decision letter the FDA sent to INVOcell?  There’s no mention of these dates anywhere else in the letter, and it’s not the submission date (that would be Feb 23, 2015).

https://www.accessdata.fda.gov/cdrh_docs/pdf15/den150008.pdf

Does anyone know?  I’m just trying to figure out how de novo timelines work.  Thank you!