Social media has good advantages and disadvantages for feedback. There are a lot of trolls on social media that lie and purposely give bad feedback even if they don't need it.
Using social media is good for feedback as it's a free, ongoing form of feedback that does not need to be heavily watched or a big budget put into it.
https://www.youtube.com/watch?v=c83E2V0r0ho
One of the top comments is "Comics Mantis is so different from MCU comedy Mantis. I don't think people will understand how much of a fighter she's supposed to be" - Marvel can consider this comment and change the narrative of the character before it releases.