I am closing my first rental Fannie Mae loan which will pay for acquisition and rehab cost, 15% down only.

One, is a Fannie Mae or Freddie Mac guideline (referred to as conventional or conforming, loosely the same thing), which is a baseline guideline to be able to sell those loans on the secondary market because they meet the GSE guideline, and then on top of that, the individual mortgage lenders may have their own set of guidelines that  go over the top of the base guidelines. 

Fannie Mae allows 50% and I believe that Freddie Mac does as well? 

Fannie Mae multifamily loans are to a company, not individuals.

I found a Fannie Mae Duplex that I liked.

Generally speaking there are 2 main types of loans for investors: “Conventional” and “Portfolio”Conventional - I'll define these as loans that come from Fannie Mae and Freddie Mac (if you recognize those names).

I'm not familiar with Quicken Loans product lines, but they usually follow conventional (Fannie Mae) and FHA guidelines and lending programs.

So it appears that the mortgage company called in the outstanding loan balance to fannie mae. 

The latest Fannie Mae sale was for 3,400 loans.

Like you'd see at a "big box" bank, via Fannie Mae, Freddie Mac?