You're lost again, this is the PVP forum. There is no endgame content here.
Correct me if I'm wrong but "endgame content" means "content played when you reach the maximum level cap". By any definition the 50 PvP bracket is "endgame" in any and all sense of the word. It has an ever progressing gear grind, just like PvE, hence 50 warzones are "Endgame PVP Content". Le gasp.