Now if Britain is leaving, English could be considered as a neutral language so no country has an advantage.
It is also still the only language that is taught as a foreign language in close to all primary and secondary schools in the Union. It's the most spoken language in the Union. It's relatively easy to learn as a foreign language. It's also the de facto language of international trade, of science, of culture and of international diplomacy (sorry France).
True, but Ireland is less than 5M, 13 seats in the EU parliament. They are not seen as a competition to anyone. The UK is 66M with 73 seats in the parliament, member of G7 and one of the most important economies in the EU.
Surely the case for English as a working language is now stronger. Previously it could have been seen as unfair to use one member state's language over another...