I think it's probably space debris. NASA probably cut the video for two reasons: a) They knew conspiracy theorists would claim they're UFOs ... b) There's more space debris up there than NASA want to admit. If people did know just how much is up there, there'd be pressure on NASA to clean it all up, and that's billions of dollars spent for no actual gain, far better to keep quiet about it, which is probably why NASA doesn't counter the claims they're UFOs.
If NASA really wanted to hide UFOs, why let the footage get out at all? It's on a delay, so they could have cut the live feed before it went out. I don't believe someone there looked up at the screen from doing the crossword and went "Oh crap, better cut the feed quick!". To quote Ros from Monsters Inc, someone's always watching.