This is golden. So many people cannot understand what "pay to win" actually is. Let me put it in simple words. Pay to win=obtaining power advantage that can only be obtained though that payment. Aka no other ways to get it. NOTHING in wow does that. The boosting guilds are doing, simply speeds up the process. Its there for everyone. Still not convinced? Name ONE item that gives you power boost, which you can ONLY get by paying irl money. Just one!
I can give you example: When you play in private server and the GMs give legendary items to "patrons" or such, after closing the original means of obtaining them.