Since this creator/director speaks about historically correct references for scripts and story lines we are wondering why this choice was made as it seems unlikely it would be incorrectly pronounced in this context. Many thanks!
Parisis is a valid Latin form of the toponym "Paris". Other variants include Parisii, Lutetia, Loticia Parisiorum, and Parisius. Without further context of use, I can't tell you 100% if it's an accurate use, but it doesn't look wrong.
For major Latin toponyms, see Graesse's Orbis Latinus, digitized here: http://www.columbia.edu/acis/ets/Graesse/contents.html