Pretty sure Dec 1 is for civilians turning in their packages to NRD. Dec 11th is the deadline for active duty service members. Don’t quote me on that, but it may be like this because us currently serving have medical facilities and authorities that can perform all the tests and checks to clear us for flight physicals and to certify documents and such. So they may screen your applications prior to the deadline of the 11th, while the currently serving shouldn’t need that extra look over.
Also, don’t believe these rumors about pilot selections being closed off, unless there is an official announcement, then there is nothing to worry about. I’ve contacted the CNRC and they did not mention anything about what I’m reading in this forum. Navy recruiters and ORs will tell you what they believe through rumors they hear, or they’ll come up with something to deter you from making their job harder. Just apply and wait for results, worst thing that can happen is you don’t get selected.