Initial support to translate the title of a translation was provided in T225494, but it applies only to new articles (not expanding with a section), and no control is provided to users.
When translating an article an initial translation of the title is provided. However, users don't have a way to either know where it is coming from or selecting a different provider if multiple were available (as the can for other paragraphs).
This ticket proposes to show the machine translation drop-down for the title like it happens for other paragraphs. This will include the translation services available as well as options to copy the contents from source and tarting from scratch.
This approach will be applied on desktop to both cases: (a) creation of new articles, and (b) expanding an existing article with a new section.