I don't think that's what they're getting at Tally, if you had 90% map completion it'd be hard not to be level 80 due to the XP given out for doing the various hearts, skill points etc. None of my characters had more than 50% work completion and they were hitting 80. Heck I didn't start my personal quest on one of them until level 70 (great way to get the last 10 levels btw) and he had something like 40% map completion at level 70.
Granted if people use dailies etc then it can artificially boost their levels but it genuinely would be hard not to ding 80 with a high map completion, you'd have to avoid most other forms of gaining XP.
Granted if people use dailies etc then it can artificially boost their levels but it genuinely would be hard not to ding 80 with a high map completion, you'd have to avoid most other forms of gaining XP.