To be completely fair, that one isn’t even an Alliance trailer, as we don’t really get any Alliance character development or depth. The main purpose of the cinematic was to point how how Saurfang felt and to kickstart the Saurfang Rebellion.
Now that said, there’s nothing particularly wrong with all the post trailer cinematics being about Saurfang. They are building him up to replace Sylvanas after all. It’s just…wish they would just rip the bandaid off and just admit that this is where the story is going instead of being coy.