Hey @WraithWalker102,
Just to clarify a couple things, Cross Progression allows you to access the content on a single EA account from the platforms connected to that account. However, it is not possible to transfer or merge progress across separate accounts entirely.
So, if the progress was made on a separate EA account, there would not be a way to combine that with the current account, and you would not see that content when logging into this account.
Additionally, unlinking any platforms will cause you to lose access to the progress made on that account. Since the progress is stored on the EA account and not individual platforms, linking your PSN to a new account would also cause that progress to become inaccessible.
To correct that, you would need to re-link to the original account where the progress was made to try restoring access. If that's a possibility it would be best to get in touch with support so they can try to help get things re-linked to the correct original accounts. If necessary, you can create a new case here and select Game Support > The EA app > I want to update my EA Account information to get in touch with the support team so they can assist with that.