According to The Verge, an email chain has surfaced during the Epic vs Apple trial that confirms this.
According to the report, when Epic Games CEO Tim Sweeney said that "Dropbox wasn't even visible on the first page [of search results]," Apple app search lead Debankur Naskar wrote in the reply that "we are removing the manual boost and the search results should be more relevant now".
Sweeney confronted Apple over its Files app showing up first when searching for Dropbox.
Apple, however, argued that it was not actually the case, the report said on Friday.
According to the tech giant, the Files app had a Dropbox integration, so Apple put "Dropbox" into the app's metadata, "and it was automatically ranked higher for ‘Dropbox' searches as a result.