You do realise that gold serves both World of tanks and World of Warplanes? They have a unified currency for 2 of their games but not for their 3rd (when they told players they would).
I only have a modest amount of gold in WOT (<500 IIRC) and don't really play it any more, but I'm now far less likely to dive into tanks from warships because I'm not willing to purchase 2 sets of mutually exclusive premium currency for games on the same ecosystem. It makes no sense for the consumer.