Probably made by a non-native English speaker. Prepositions are so unique to each language and oftentimes seemingly randomly chosen (is that à, de, sur, or no preposition at all, French?). If you roughly know a one-to-one translation of the prepositions from your language into English, you can often get it wrong just like this.
En France, Au Canada, À New-York, Aux Seychelles, À Cuba.
Don't try to find a logic, there literally is none and anyone who tells you otherwise is just retrofitting rules to chaotic data and will inevitably have a list of exceptions longer than a French politician's criminal record. Half of it is literally just "what was grammatically fashionable at the time this toponym was discovered/imported/created".
This does not excuse English's abuse of prepositions though. Why do I get on the bus but in the car? Why, English?
When I was doing farm work, the Mennonite colony nearby who provided meals had a vertical butter contraption for cobs of corn. You just stick it in, rub it around and presto, perfectly buttered corn.