I'm new here myself so I hesitate to give advice.
However, I know from my own uploaded gedcom that if I had John Brown who married Sarah Cox, I had to manually go in and change the 'current last name' field from Cox to Brown.
I expect many who uploaded their tree needed to do this but did not notice.
There are also some wikitree users who strictly and particularly do not change this field, as in some societies the maiden name really was used even if the person was married.
So if the profiles have a profile manager, I would send a friendly and casual message asking if they wished it to be changed, rather than just go in and change it.
I agree, however, that to have both maiden and married surname showing up in a surname search list helps to avoid duplicates.