btw it’s v v likely that Viktor’s fans (and probably commentators and other/older skaters) affectionately call him Vitya, like Evgeni Plushenko was often called Zhenya, and Yuzuru Hanyu’s fans call him Yuzu and Javier Fernandez’s fans and many commentators (and Yuzuru) call him Javi and the signs fans bring to competitions have ‘VAMOS JAVI’ on them. Commentators, fans, etc, using a celebrity’s nickname, especially in competitive sports (football, hockey, etc), to talk/tweet about them and cheer them on and give them letters or gifts, or even speak to them sometimes, is very common. Especially if the nickname is a common one (like Vitya is since Viktor is a relatively common Russian name) and not necessarily super personal. Johnny Weir’s been calling him Vitya Nikiforov in his tweets too :)
So everyone in the figure skating world is likely a) aware that Viktor’s Russian nickname is Vitya, and b) use it fairly often.