"At the hotel, he will be able to go online."
Translation:À l'hôtel, il pourra se connecter à Internet.
France had computers long before they had Internet access. There must have been a term in use for equipment that was online or for putting something online. It probably made no sense to speak of a person going online, and made no sense in English either.
In the US, we had a service called America Online, giving the impression that people could be online. It was before there was general access to the Internet or any Internet providers for the general public, so people going online became a thing.