It's funny that everyone says it like that, in the section "Descriptions on how Xavier can be used for name bullying" on this site: https://babynamesworld.parentsconnect.com/suitability_of_Xavier.html, two people called Xavier say:
- Purposely mispronouncing: Saying it 'eggs-avier' instead of 'zavier'
- Wrong pronounciation: They say xavier like (eggs a vior) but that is wrong.
And the site says pronunciation is : (ZAYV yer); (GZAHV yeh)
I've never heard Exavier, even in the US (I'm French/US). I just checked out X-Men to hear how they say Exavier.
I guess all depends on how the parent's pronounce it in the first place.