Apparently the mystery box got smashed wide open and a big fat spoiler on TFA got dropped today (stay away from the usual fan sites and spoiler forums if you don’t want to know).
1) Big fat hairy spoilers getting out is inevitable for any movie, especially this one. Star Wars fandom got used to craving spoilers the last time around and there’s no reason to expect that to change.
2) Keeping fans too much in the dark doesn’t stop the leaking of big fat hairy spoilers, so you might as well keep fans informed. Frankly I miss the webcams, videos, select stills, and other things that kept even non-spoiled fans guessing and talking the whole three year wait.
3) Even if a big fat hairy spoiler is true, it doesn’t mean that scene will make it in the film (it could be cut or re-shot) and it may not play out in the film as it is shot in a studio.