Yeah fingers crossed that it's good. FMAB's first episode was all original content and not from the manga, and it existed only to help explain the story to newcomers, and more importantly, gave a bunch of action sequences that they used for trailers prior to release. Maybe a similar situation is going on here, but this looks more like a reimagining to me.

This is not a faithful retelling... The story and characters, from what's shown in the trailer, appear to be further from the source material from the original.