The funny thing about lore is that it doesn't become false until it is retconned. The SC do not change that statement because ,the Silver covenant have never been numerous . Them traveling around doesn't make them numerous. Vereesa being in Wotlk and Legion doesn't mean there are two Vereesas. The Sc is effectively reliant on the Kirin'tor for its survival, so it makes sense they are usually near Dalaran forces. That doesn't make them numerous.
and the "void elf" ptr which I assume you are talking about is right now only weapons. The only High elf in the beta right now is Alleria .