If Blackburn did sign during the November, early signing period - he's coming. Certainly unforeseen situations (injury/MJ) can arise, but you don't sign an NLI unless the absolute expectation is your coming in the fall. The aid agreement all of these players (and the school) signed was for the 2015-16 school year (you cannot sign for future years), which begins this fall.
So it looks like Miller is the odd man out - I can't imagine they'd bring in six forwards - and the forward class is Blackburn, Vela, Nazarian, Cefalu, Kalinowski.
CHC - the NTDP tweeted about many of their NLI signees during the recent U18 Tournament, bunt mentioned nothing about Masonious. Have you heard anything? Hopefully, UNH is just waiting until he returns stateside...??