Is Bioware playing it safe?

I'd say so, The premise of an entire new galaxy is daunting and certainly a step into the unkown, but the trailer reveals that Bioware still places great value upon existing tropes and styles, Great mysteries, beams of light, an ancient evil, etc. The way it's paced feels very similar to what has been done before. Then there is the premise, which is intentionally ambigious about it's specifics (Remember Lazarus?). This is fairly standard for the kind of story Bioware is aiming for; We're not supposed to worry about how the Andromeda project got about or the technicalities of the ark construction. If Andromeda was the first of the franchise I'm heavily inclined to agree with this line of thought, however because we have an established universe with a detailed knowledge on it's history it becomes a lot harder to squeeze in major chain of events and making it appear legit.