This post claims that Anna Wintour, the lead chairperson of the Met Gala, posted a video explaining why she banned Donald Trump from the event. In the linked video, a user on X reposts a TikTok video where it appears that Wintour does make these claims via an interview. Despite this, when searching for more information about where the "interview" took place, multiple sources claim that the user on Tik Tok, @kiu1384934c, deep-faked (digitally altered) the video completely (Yahoo). The video has since been removed from the original Tik Tok account, further suggesting its lack of credibility. The interview footage is actually altered from a video published by Vogue in 2019 where Wintour never mentions anything about Trump (Vogue).
Although this claim and reposted video are fake, Trump is likely banned from this years' Met Gala. On the The Late Late Show with James Corden in 2017, Corden asked Wintour in a game of Spill Your Guts or Fill Your Guts who is someone she will never invite back to the Met Gala. In quick response she says Donald Trump to which the crowd loudly applauses (YouTube 5:50). This is likely in response to his political presence as Trump was a regular attendee to the Met Gala up until 2012.
Although the video is clearly deep-faked, the artificial Wintour's statements could be likely true to what she actually thinks (My personal speculation). I only include this since I believe that's what is making this video believable to some. Overall the original claim is completely false -- Wintour a) never posted this video and b) the video is an artificially edited interview.