Hi, please know QnA currently only supports the products listed in right-hand pane (more to be added). Better to reach out to subject matter experts in dedicated forums over here.
For the issue itselft, to let you know, from some site the information seem to state that you can migrate your data to Outlook 2019 if the Entourage folder has not been deleted.
See there;
Catalina update and possible loss of mails and contacts on Entourage
Outlook 2019 can import your contacts and mail from Entourage 2008 as long as you don't delete the Microsoft User Data folder. The instructions for Outlook 2016 and 2019 are the same.