There are several reports on the internet that mention that Bethesda has announced. An official tweet from Bethesda confirms the reports.
We’ll have more information to share in the coming weeks and months about The Elder Scrolls Online and DOOM Eternal on Xbox Series X and PlayStation 5 including expected release windows and a list of enhancements.
https://bethesda.net/
Some clarification was provided on the ESO official forums.
Just to clarify: you will be able to carry over your progress no matter what. It’s just that the upgraded version will not be available immediately upon the launch of the Xbox Series X and PlayStation5.
https://forums.elderscrollsonline.com/