You're "off" on a few things & I think everything you're looking for can be found on the basic, 2 page NT filing:
FY End was 12/31/2016.
They get "90" days to file, not 75.
Had to file the report, or the extension by 3/31/17, which they did by filing the NT.
They get 15 calendar days FROM 3/31 to file actual report so it is now due by 4/17 due to 15th being Saturday.
With that said, can you tell me specifically what you consider "good news"?