When someone registrates on chess.com, they get to choose a new rating. But it is sometimes not accurate, so their rating fells down. But the starting rating will still be listed as their highest rating, which is unfair (example: 1200 starting elo, 400 final elo). There should be a "?" Icon, which would mean that their rating is not established. When it establishes, then the system starts to measure the highest elo, average opponent rating, etc.
Honestly it doesn't really matter, almost everyone's rating will drop, so that one will be listed higher, but whenever I see 400, 800, 1200, 1600 as ratings I assume they haven't played yet, and I think most of us do.