Board Thread:Support Requests - Getting Technical/@comment-2153169-20150215154911/@comment-1038387-20150215160246

Yep, it's a new feature. However, it's not linked to location, but to preferences.

I'm Dutch, but have language set to English. I don't get the blue banner on English wikis, but I do get it on Dutch wikis - saying it also exists in English.

So the easiest way to get rid of it (easy if you only edit on English wikis) is to set your Preferences to English. First tab, first dropdown of "Appearance".