Brexit and the English language

Countries that used to belong to the British Empire, on which the sun never set, tend to use the English language as their official language. Even in Japan, which was defeated by the US a little more than seventy years ago, some people think that English should be designated as the "second official" language. Do most French people speak German more fluently than they speak English? Do most German people speak French more fluently than they speak English? I imagine that English might be treated as the de facto offical language in the EU. (My guess is that both English with a strong German accent and English with a strong French accent will be used when there are no highly-competent interpreters around them at their meetings. With no native speakers of English around them, people might be happy and content with their English with their strong accent.)