@Thestia
possibly because there is a clear legal distinction between the two terms.
"Refugee status" is applied after a by migrant/immigrant is appv'd by the US Fed govt. Until approved, technically the applicant is still considered a migrant/immigant by legal standards

Personally, i know people from Mexico, Guatamala, and Nicaragua that I absolutely felt heart & soul *deserved* to be recognised as "refugees", but never were. At least none of my friends were forced to return...yet.