In some tech companies in Europe, English is the default working language locally as well as remotely. If you have staff spread out among multiple countries, it’s more or less the default option because it’s the one language most people will have in common. I have a friend who works in tech in Berlin and he says despite most of the staff of his company being German, they all use English as a working language, so much so that he’s not had to learn more than basic German to be able to live and work there.
My experience with French tech companies and my French friends who work for them suggests that French is very much the working language day to day. It would be interesting to know how it works within Asobo, given their close working relationship with Microsoft and other (presumably) primarily English-speaking groups like Working Title and 3rd party devs.
Using job postings to work out what companies are working on is a time-honoured technique, though, along with checking patent filings 