I think that Chespin's English name may be partially based on French like the Japanese name. A lot of French words end with 'in' (fin, butin, déclin, jardin, coussin, escarpin and hundreds more). Also, the French word for rabbit is 'la'''pin'''' while one possible name for a male rabbit (and hare) is 'bouqu'''in'''' Chespin certainly appears to be based off rodents, which hedgehogs, contrary to rabbits and porcupines, are not. I've also heard rumors that Chespin's evolution is called 'Chespinne' which would be the natural French feminine form of 'Chespin', like a female rabbit is 'lapine' and a female lion is 'lionne' (the male form being 'lion'). There's just something about Chespin's name that seems to have a French air to it, and it would be easily pronounceable in French though the pronunciation would differ greatly from the English one. And the fact that Fennekin also has that very French-y suffix 'in' seems to confirm the speculation that the new region draws inspiration from France, at least partially.
Maybe it should be added in the article that the French word 'marron' does not only mean 'chestnut' but also 'brown', the name including all shades of brown and not a particular shade like the English word 'maroon'. This could be a possible double entendre as Chespin is both brown and based on a chestnut.
Though this may be reaching too far out, the primary meaning of 'urchin' in English is 'a young boy who is poorly or raggedly dressed' or 'a street boy' which would translate into 'gallo'''pin'''' in French, according to google translate. 'Gallopin' is a slight pejorativ for a young, playful (street) boy like the English 'lout' or 'guttersnipe'. Another French word for the same concept is 'gam'''in'''. In my opinion, Chespin could in fact look a little like a playful and teasing male pokémon. Though there's likely no truth in this, Game Freak could have intended to play with the idea of the name that mischievous young boys share with hedgehogs: urchin. And Chespin could be the embodiment of this.