Since it says this could also affect players who have War Thunder on their Steam account but don’t use it to login, probably worthwhile to put this info here, in lieu of an actual mention yet in the regular War Thunder news.
"Dear players!
Not long ago we implemented Unicode nickname support in the game, while new Steam players now immediately get nicknames similar to their Steam nicks with some limitations.
During some technical work on standardizing the existing nickname display, we gained a malfunction leading to the reset of nicknames with some Steam players to nicknames based on their Steam nick.
This issue might also affect some of the Gaijin-accounts already linked to a Steam profile.
We didn’t plan to change the nicknames of Steam players who previously changed their in-game Nickname and within 24 hours we will try and roll back these changes for all players in order to return the nicknames or provide the opportunity to change the nickname for free.
We apologize for any inconvenience. We will do our best to fix this problem as soon as possible!"
(link)