Depends what you mean by "an actual term". Any piece of language that is in use has been coined ( or "cooked up") by someone. that doesn't stop it from being an actual term.
The term "emergency socialism" seems to have some very limited currency prior to this year, for example in a document from 2017, dicussing the history of Socialism in the UK:
The desirability of some form of
‘emergency’ socialism with a dictatorial colouring briefly won a broader
range of labour movement adherents in grim crisis years of the early
1930s (including Clement Attlee), but never since.
This seems to refer to the belief that in an "emergency" (such as a fascist/bourgoise alliance taking over the government of the UK) then a worker's revolution could be followed by a period of proletarian dictatorship. Emergency socialism is, therefore, the imposition of socialism to address an emergency.
Clive Lewis MP said that the Green New Deal can’t just be about “tinkering” and instead called for “emergency socialism”, which he described as a “whole new political economy”.
Lewis urged for the UK to show international leadership as one of the first countries to industrialise, adding that trade and foreign policy “need to be part of the Green New Deal.”
Likewise, in this article from last year, "emergency socialism" is a socialism intended to address a particular emergency (climate change) instead of a general worker's movement.
Note that both these sources use quote marks, indicating that there is little currency in the term "emergency socialism".