Hello,
How a player, who has always been on the lists of different servers and that suddenly it disappears from all lists.

If a server has been "removed" from the GT database, all player statistics for that specific server will also be removed.

This alongside, the fact that server owners can derank players—are the only two feasible explanations.

Can you provide us with the player name that you're referring to?

Hello, I dont want to say the name of the player to not cause him problems. However, what I do know is that the player dont exist in the list of all servers and his name no longer exists on GT. If he closed his account completely on GT, he could play under another name too?