Section translation uses machine translation (MT) to provide an initial version of the contents. Links labels are translated by the Mt as any other piece of content. However, in some cases it may be more convenient to use the article title instead.
A similar request was made for desktop in T197662: CX2: Quickly switch between alternative link label translations. This ticket focuses on mobile support for it.
This issue surfaced in recent research with Bengali Wikipedia editors:
[...] the text for links may often get literally translated, when what is needed is a transliteration of a proper noun. For example, one editor needed to modify link text because the name of a newspaper had been literally translated instead of transliterated.