When I first looked into the spaCy library, I saw that the lemmatizer is executed after the PoS-tagger and all the information from previous steps are provided to the next one. Now I know that "providing them" and "using them" is quite another cup of tea.
If you wonder why someone else is mentioned as author, I wonder that too... I think it is because they removed me from the system?
Link to the full blog post.