Published Data sources are only usable from within Tableau (either Server or Desktop) AFAIK.
What are you looking to do with Excel?
Thanks for your reply.
I am trying to figure out some re-usability of the Datasets, which our Finance Risk Team can use in Excel.
For ad-hoc risk modelling, sometimes, they prefer to use Excel.
That's why integration with Excel is important for us.
BTW, Power BI Excel plugin supports that for their published datasets.