So far, the trailer shows that the jaws clamp on her arm and some sprays of blood, but we're not explicitly shown her severed arm or the stump. It does seem to show that she keeps getting fucked after she loses said arm for a while, and there's no way to know exactly how the trailer was spliced together out of the final scenes. It also shows the thing closing its mouth completely, chewing, and spitting out her skull, before she wakes up again.
A description of the product implied that she basically meets a bad end and wakes back up again as if the bad-end was a bad dream, which is pretty much in line with most of the final bad-ends, and only the multi-stage ones are different in the game.
There's no way to know how many bad-ends they'll cover in the first episode, assuming that there will be more than one.
Either way, I'd have been thoroughly surprised if the devs agreed to an animation without some kind of gore happening. It wouldn't be true to the game, and the animation is both meant for the fans of the game as well as to potentially get more people to buy the game. Imagine if the animation had zero gore in it, and then someone went to the game and discovered what it was REALLY like... it'd definitely cause problems.