I have yet to find a Nahuatl place name that Mexicans pronounce the original way. Examples:
- Spanish pronunciation: [ˈmexiko]
- Nahuatl pronunciation: [meːˈʃiʔko]
- Spanish pronunciation: [sotʃiˈmilko]
- Nahuatl pronunciation: [ʃoːtʃiˈmiːlko]
The Nahuatl word "Huaxyacac" [waːʃ.ˈja.kak] was transliterated as "Oaxaca" using Medieval Spanish orthography, in which the x represented the voiceless postalveolar fricative ([ʃ], the equivalent of English sh in "shop"), making "Oaxaca" pronounced as [waˈʃaka]. However, during the sixteenth century the voiceless fricative sound evolved into a voiceless velar fricative ([x], like the ch in Scottish "loch"), and Oaxaca began to be pronounced [waˈxaka]. Source: wikipedia.
Are there any exceptions to this?