Here we see an initial set of languages is offered,
But shouldn't Chinese be one of them? It's the world's most spoken language.
That will save users from having to search.
Here we see an initial set of languages is offered,
That will save users from having to search.
Kind of related: T258244 "Show user babel languages at top of language selection for monolingual language selector" and/or add browser language to the list.
It's possible to use the quickList parameter when initializing ULS with the .uls() function. You can see some examples in https://codesearch.wmcloud.org .
Which languages to put there is up to the designer and the product manager. Putting the user's previously selected language there is probably a good idea, and maybe you can think of some more. You can take some ideas for picking suggested languages from Compact Language Links.
My own suggestion is not to invest too much effort into it: Compact Language Links are targeted at users, so we need to optimize a lot there and make a lot of guesses, whereas file uploading is for editors, so you can make something simpler. Our user research showed that most people can easily find languages by using the search box and without scrolling.