Why do you assume Pittsburghers are pronouncing Versailles wrong? Maybe its the French who are pronouncing it wrong!
And in case youre at all curious about Pittsburghese, 16 Words Youll Only Understand If Youre From Pittsburgh:
https://www.onlyinyourstate.com/pennsylvania/pittsburgh/words-pittsburgh/
Thanks for the question. I don't assume. I know. There is a cosmic certainty to this question. Absolute knowledge. One correct answer. :-)