I've seen a lot of complaints about this movie already, from when the description of the plot and the changes in the story to the casting. Now, I know some criticisms are valid in terms of how Disney might handle something from another culture (I know people criticized the animated movie for its handling of the actual Chinese folklore heroine and even the culture), which is understandable and I have no qualms with people being wary in regards to that, however I've seen far more complaints about the lack of Mushu or Shang or the songs from the animated movie. And all I have to say to that is....yeah, and?
Most of these live-action remakes tend to deviate from their animated movie counterparts in some way (and the animated movies, in turn, also deviated from the original sources quite a bit). Movies like Maleficent was more of a re-imagined retelling of Sleeping Beauty, and Cinderella was just a basic telling of the story that had absolutely no resemblance of the animated movie at all. Neither movie featured any of the songs in them, yet both those movies were, imho, probably the best of these live-action remakes. Now when Beauty and the Beast came out it was nearly precisely the same as the animated movie, but it was met with mixed reviews. Many criticized it for trying too hard to be just like the original without adding anything interesting or new to advance the plot and how the songs seemed autotuned. Keep in mind that not every live-action remake has been the same. Some have the musical numbers while others don't at all, some focus on the same story while others a retelling, etc. So it really does vary depending on what they decide to do.
I personally think deviating from the animated movies is probably the better option since it avoids trying to compare to the originals. Because while I understand the sentiment of people wanting things to be exactly like the original, to see certain scenes and such played out in a live-action version, nothing can or will ever live up to those expectations that worked so well for the animated movie. Don't get me wrong, I've been vocal about my indifference towards these remakes in general and that hasn't really changed, I still think they're pointless. However, if there is to be a middle ground I would rather have a remake that does something different than a remake that is just a frame-by-frame retelling of something already done better in animation.
With Mulan, while there are some things I do question, I'm actually okay with the different direction they seem to be taking.
I'm just really happy that there's an all-Asian cast, and based off the teaser alone it looks gorgeous, the cinematography and what seems like the choreography for the fighting sequences. It also seems void of any noticeable CGI, which is quite refreshing. That's not to say that the next trailer there won't be something like that, this is our first glimpse after all, but so far I'm liking what I'm seeing. This will be one of the few remakes I will be anticipating for, tbh.