Here are the quotes you mentioned in their entirety,
The letter says the CP was denied due to a technicality and has nothing to do with the sNDA,
Quote: Because your request disputes the appropriateness of listing the '146 patent and urges FDA to remove it from the Orange Book, your request is subject to the procedures and requirements set forth in our regulations at 314.53(f). Submission of your request to FDA in a citizen petition does not comply with those procedures, and we are unable to resolve your concerns in a citizen petition response.
Or...if he wants to dispute a patent to the FDA, it has to be submitted through appropriate channels as dictated by FDA regulations, not a citizen petition...
Again, the other two CP he submitted, one of which does pertain to the sNDA (submitted 7/17/19), are still pending.
Looking back, it appears there is some truth to that. Amarin received a CRL on April 27, 2015 (hyperlink). On that day, the FDA denied all 22 citizen petitions (see FDA-2013-P-1612-0429 thru FDA-2013-P-1612-0453).
Currently, there are two citizen petitions still open that were submitted by MRC. While keeping an eye out for denial letters may warn us in advance of sNDA approval, I don't know how predictive it will be if history repeats itself and they accomplish both on the same day.
The FDA denied all 22 CPs the same day they issued a CRL to Amarin in 2015. The CP they denied yesterday was due to a technicality (they went so far as to provide instructions how to submit patent disputes correctly in the rejection letter). There are two remaining CPs, one of which is related to the sNDA.
If you require additional clarification, to put it metaphorically, using the remaining citizen petitions as a 'canary in a coal mine' (hyperlink) to warn of impending FDA approval for Amarin's sNDA may not be effective because historically FDA action and petition rejection occurred at the same time. But of the two petitions remaining, the petition submitted on 7/17/19 would be the most telling because it directly relates to the sNDA.