The reasons why some of your products not updated Ali Express link after you do "Sync with Oberlo":
Your products are NOT from AliExpress.
Your products are NOT imported by Oberlo.
You have to come back to your AliExpress site, get the link of your products and try to sync product one by one.
Should you have any other concern, feel free to let us know via our live chat channel by clicking on the bottom right icon inside app, or our email at email@example.com.