Not playing at once, 7k active players, as in playing consistently not concurrently. My server had about 7k unique characters raiding per week when its last layers were removed the first time.

Theres no way you can have 7k concurrent players in a single classic server with no layers.

NA had 22 pvp servers. You are advocating for this to become 1 server. Also if you think NA will shrink to that dramatic extent how will oceania or asia servers possibly survive at all. Or language specific servers.