When you export a Gedcom from Ancestry to Wikitree, any sources attached come with it. However, they are not in a format accessible to anyone that doesn't have an Ancestry subscription. They can see the Gedcom detail, but not all the content in the source.
If you later export the same info via Gedcom from another family tree software to Wikitree, you will be asked to exclude duplicate profiles prior to Gedcom approval.
Ancestry hints will still come up for records that you do not already added to your Ancestry tree.