This is faulty thinking because you already ARE at the same level. You are given the same opportunity to acquire the exact same gear that those Mythic Raiders take in to the next raid. So if your gear (now) is causing you to be behind, then you would also be behind even if they cut out a couple of modes of raiding... because those guilds are simply better (or maybe more committed) than yours and they will simply progress faster.
In simple terms, if you are ranked 20th now, you would still be ranked around 20th then. Very little would change.
To answer your title question though, in the eight years that I played WoW, I don't think I ever once paid any attention to server rankings. I saw a few people mention things a few times and thought "cool", but I really never cared one way or another. I kind of suspect that most people didn't care really, because Raid participation was pretty low in general, and even for those that did only a handful of guilds per server were in anything resembling a race.