It's true that, following Trump's executive order to "Restore Truth and Sanity to American History," Trump was removed from a list of impeached presidents at the Smithsonian National Museum for American History’s exhibit on the American presidency, as reported by outlets like the Associated Press, the Washington Post, and PBS.
However, it should be noted that the museum denies being asked or pressured by the Trump administration to edit the exhibit's contents. According to the AP, a museum spokesperson, Phillip Zimmerman, had previously pledged that “a future and updated exhibit will include all impeachments,” though no date was given for its installation.