Why activation function is not needed during the runtime of an Word2Vec model
From this StackOverflow Question


  while no activation is explicitly formulated, we could consider it to
  be a linear classification function. It appears that the dependencies
  that the word2vec models try to model can be achieved with a linear
  relation between the input words.
  
  Adding a non-linear activation function allows the neural network to
  map more complex functions, which could in turn lead to fit the input
  onto something more complex that doesn't retain the dependencies
  word2vec seeks.