UPDATE: This mechanic has changed in Sword and Shield.
For instance, I had a Japanese Joltik named バチュル ("Bachuru"). Its name upon evolution was not Galvantula, but デンチュラ ("Dentula").
EDIT: Additionally, if you evolved a foreign Pokémon from a Generation 6 or 7 game and it gained its native-language name, it will revert to the original if you bring it to Sword or Shield through Pokémon HOME.
For example, I had a German Sneasel ("Sniebel") that I acquired in Omega Ruby. It evolved into a normal Weavile, but its name was changed to "Snibunna" when it arrived in my Sword game.
Were the aforementioned Ambipom compatible with Sword or Shield, its name would change to "Ambidiffel".