That is not always true. I know many women who always had their hair perfect and eyes perfect when dating. And now they are comfortable or more comfortable to let their natural beauty show.
On a different note:
My friend is a shadchan for a well known yeshiva and she told me that the 3 things boy looks for/demand for her to find is, size 2-4 girls, blue eyes, longer then shoulder length hair. So… I ask, when did the length of a girls hair become more important than her midos? My friend told me that he has mothers of bachurim screaming at her over the phone ” this girl was bigger than you said he would be don’t you think my son can do better what are you setting him up with”! .
Found it very interesting. And a little disappointing.