I know by default, when users navigate to the Variation Root Site, they are redirected to the appropriate top site of a variation label, based on the language setting of their Web browser. For example, if a user's default browser language is French, SharePoint Server 2013 redirects that user to the top site of the French variation label. Is there a way to make sure everyone starts with the same language despite their Regional Browser Settings ?
I know Benjamin Niaulin talked about it but it doesn't work like this:
One way to make sure everyone starts with the same language despite their Regional Browser Settings is to set it via the Central Administration in the User Profile Service Application. Of course going through each individual profile could be long, you look into PowerShell